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堀江 好文内海域環境教育研究センター教授
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- This study investigated the spatiotemporal distribution of perfluoroalkyl substances (PFASs) in the Daku River, Taoyuan, with a particular focus on source apportionment and associated ecological and human health risks. The total PFAS concentrations ranged from below the detection limits to 185 ng/L, with perfluorooctanoic acid (PFOA) emerging as the predominant compound, followed by perfluorobutanesulfonic acid (PFBS). Elevated PFAS levels were observed downstream of the confluence between the Daku River and Litouzhou ditch, suggesting contributions from industrial activities. Principal component analysis (PCA) and positive matrix factorization (PMF) were employed to identify important components and factors that explain different compounds. Factor 1 (dominated by PFUnA) was attributed to sources such as food packaging and textiles. Factor 2 (PFBS, PFHxS, PFOS) originated from agricultural inputs and wastewater discharges linked to the semiconductor and photonics industries. Factor 3 (PFOA, PFNA, PFDA) was primarily associated with fluoropolymer manufacturing, electronics, chemical engineering, machinery, and coating production. Ecological risk assessments showed no significant threats (RQ < 0.1) for PFBS, PFPA, PFNA, PFOS, and PFDA. Human health risk evaluations based on the Health Risk Index (HRI < 1), likewise, indicated negligible risk from crop and vegetable consumption in the Daku River area. These findings underscore the importance of continued monitoring and targeted pollution management strategies to safeguard environmental quality and public health.MDPI AG, 2025年05月, Toxics, 13(6) (6), 435 - 435[査読有り]研究論文（学術雑誌）
- Tris(2-ethylhexyl) trimellitate (TOTM), a non-phthalate plasticizer, has gained popularity as a safer alternative to phthalates; however, its ecotoxicological impact and environmental behavior remain unclear. In this study, we investigated the species-specific sensitivity of Oryzias latipes (Japanese medaka) and Danio rerio (zebrafish) to TOTM exposure, and determined the residual concentrations in aquatic environments and ecological risk. Embryonic and larval toxicity tests revealed significant species differences: zebrafish showed higher sensitivity, with a lowest observed effect concentration (LOEC) of 43.7 μg/L, exhibiting increased mortality, swim bladder inflation failure, and growth inhibition. In contrast, the Japanese medaka showed no significant adverse effects under similar exposure conditions. TOTM residues were detected in a single sample (348.2 ng/L) after environmental monitoring of the Sumiyoshi River over 3 months, highlighting potential environmental persistence despite limited detection. Risk assessment using the ratio of the measured environmental concentration (MEC) to the predicted no effect concentration (PNEC) revealed a value > 13, indicating a significant ecological risk posed by the TOTM. These findings underscore the importance of evaluating species-specific responses, conducting comprehensive environmental monitoring, and addressing ecological risks associated with TOTM contamination in aquatic environments.2025年05月, Environmental pollution (Barking, Essex : 1987), 126413 - 126413, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Bis(2-ethylhexyl) sebacate (DEHS), a commonly used non-phthalate plasticizer considered relatively safe relative to phthalates, has been reported to disrupt the endocrine system, affect reproduction-related genes, and potentially induce thyroid hormone-disrupting and estrogenic effects on Japanese medaka (Oryzias latipes). However, the long-term effects of DEHS exposure on aquatic organisms remain unclear; further, data on residual DEHS concentrations in rivers are extremely limited. Here, the effects of DEHS on the reproductive performance and gonadal sex differentiation of Japanese medaka were determined. Japanese medaka embryos and larvae were exposed to varying DEHS concentrations that have been reported to induce thyroid hormone-disrupting effects. The residual concentrations of DEHS in the Sumiyoshi River were measured weekly from May to July in 2024. The formation of testis-ova was induced in XY medaka exposed to varying DEHS concentrations. DEHS exposure was shown to significantly reduce the number of eggs laid but did not affect fertilization rates. The DEHS levels in the Sumiyoshi River were either undetected or below the method quantification limit. Although significant changes in reproductive capacity and testis-ova were not observed at environmentally relevant residual concentrations, this study highlights the potentially harmful effects of a chemical that was previously considered environmentally friendly.2025年05月, Journal of applied toxicology : JAT, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Zinc oxide nanoparticles (ZnO NPs) are widely used in manufacturing cosmetic and pharmaceutical products. Although previous studies have reported their toxic effects on fish, the underlying mechanisms behind their toxic effects are yet to be identified. This study evaluated the impact of ZnO NPs on marine medaka's survival, heart rates (Oryzias melastigma), and the expression of genes linked to neurotoxicity and cardiovascular toxicity. Marine medaka samples were exposed to ZnO NPs at varying concentrations: 0.01, 0.1, 1, and 10 mg/L. Survival rates and heart rates were monitored on the 12th day postfertilization. Gene expression related to neurotoxicity (α-tubulin, elavl3, gap43, gfap) and cardiovascular toxicity (cdh2, atp2a1, cacna1da, crhr1, ahrra, arnt2) was assessed by performing real-time polymerase chain reaction. The survival rate of marine medaka samples was not significantly impacted by exposure to up to 1 mg/L of ZnO NPs; however, exposure to 10 mg/L of ZnO NPs resulted in a 60% reduction in survival rate. The heart rate of the samples did not significantly change across all concentrations. High ZnO NP concentrations (10 mg/L) significantly suppressed the expression of neurotoxic and cardiotoxic genes, including elavl3 and gfap. ZnO NPs exhibited dose-dependent toxic effects on the marine medaka samples by affecting the expression of genes related to neurological and cardiovascular functions. These findings underscore the potential risks of ZnO NPs to aquatic organisms. The distinct toxic actions of ZnO NPs and dissolved ions complicate the interpretation of results, as this study did not measure ion release, a critical factor in understanding NP toxicity. Moreover, ZnO NPs may cause oxidative stress and disrupt cellular pathways. Furthermore, without distinguishing between NP and ion effects, it is challenging to determine the exact cause of toxicity. These findings highlight the need for future studies to measure dissolved ions and particles separately to clarify their contributions to toxicity, where the mechanisms of action are still debated.2024年10月, Journal of applied toxicology : JAT, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Anthropogenic particles in sea surface water of the semi-enclosed Osaka Bay were identified using stereomicroscopy, classified according to polymer type using Fourier-transform infrared spectroscopy (FTIR), and categorized according to their physical characteristics. A total of 565.1 particles were detected in the water samples. However, plastic particles accounted for only 22.4% of the particles. Microplastic abundance in Osaka Bay showed seasonal variance from 8.9 ± 1.4 (in May) to 22.8 ± 6.5 particles/L (in July), which is consistent with previous reports in other semi-enclosed bays. Microplastics were mainly fragmented and fiber shaped, with gray and colorless/white coloration. The dominant polymer types were polypropylene, poly(methylmethacrylate), polyester, polyethylene, and polyethylene terephthalate. Generally, there were considerably higher abundances of microplastics at offshore sites compared with nearshore sites. The results of this study suggest that local river effluents and marine-related activities are probable sources of microplastics in Osaka Bay.2024年07月, Environmental science and pollution research international, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Phenytoin, an antiepileptic drug, induces neurotoxicity and abnormal embryonic development and reduces spontaneous locomotor activity in fish. However, its effects on other endpoints remain unclear. Therefore, we investigated the effects of phenytoin on the swimming behavior and reproductive ability of Japanese medaka. Abnormalities in swimming behavior, such as imbalance, rotation, rollover, and vertical swimming, were observed. However, when phenytoin exposure was discontinued, the behavioral abnormality rates decreased. Phenytoin exposure also significantly reduced reproductive ability. By investigating reproduction-related gene expression of gnrh1, gnrh2, fshb, and lhb remained unchanged in males and females. In contrast, kiss1 expression was significantly suppressed due to phenytoin exposure in males and females. kiss2 expression was also significantly suppressed in females but not in males. We filmed videos to examine phenytoin exposure effects on sexual behavior. Females showed no interest in the male's courtship. As the kisspeptin 1 system controls sexual behavior in Japanese medaka, phenytoin exposure may have decreased kiss1 expression, which decreased female reproductive motivation; hence, they did not spawn eggs. This is the first study to show that phenytoin exposure induces behavioral abnormalities, and suppresses kiss1 expression and reproductive performance in Japanese medaka.Elsevier BV, 2024年06月, Aquatic toxicology (Amsterdam, Netherlands), 273, 107007 - 107007, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Plasticizers are considered as newly emerged contaminants. They are added to plastics to increase their flexibility and softness. Phthalate plasticizers including the Di-2-ethylhexyl phthalates (DEHP) are toxic and induce adverse effects on the different organization levels of the environment. In the current study, we investigated the potential toxicity of DEHP using Zebrafish as a biological model. Five ascending concentrations of DEHP were tested in embryos throughout 96 hpf: 0.0086, 0.086, 0.86, 8.6, and 86 mg/L. Embryotoxicity assessments revealed limited lethal effects on DEHP-exposed embryos, yet notable anticipation of the hatching process was observed at 48 hpf. Although DEHP showed negligible influence on the length and pericardial area of exposed embryos, it led to multiple bodily deformities. Gene expression analyses of key cardiogenic and inflammatory genes evidenced alterations in tbx20, bcl2, and il1b expression in Zebrafish embryos at 96 h post-fertilization. Results from the cardiac function analysis displayed that DEHP significantly affected the arterial pulse and linear velocity within the Posterior Cardinal Vein (PCV) of exposed fish. These findings strongly advance that even at low concentrations, DEHP can be considered as potential toxic agent, capable of inducing cardiotoxic effects.2024年06月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 109956 - 109956, 英語, 国際誌[査読有り]研究論文（学術雑誌）
- Owing to growing concerns about the adverse effects of phthalate plasticizers, non-phthalate plasticizers are being increasingly used as their replacement. However, information on the residual environmental concentrations and ecological risks posed by these plasticizers is limited. In this study, we analyzed the environmental contamination of 11 phthalates and 5 non-phthalate plasticizers in Class A and B rivers in Japan. In the considered river water samples, phthalates and non-phthalates were detected in the following order of detection frequency: phthalates (DEHP > DMP > DMEP > BBP > DNPP > DNP > DEEP > DBEP = DNOP) and non-phthalates (ATBC > DEHS > DEHA > TOTM = DIBA). Phthalate plasticizers were the most abundant and included DEHP (157-859 ng/L), DMP ([査読有り]研究論文（学術雑誌）Antiepileptic drugs, such as phenytoin, are often leaked into aquatic systems through sewage facilities due to their low metabolic rate. Fish, such as the Japanese medaka (Oryzias latipes), demonstrate abnormal swimming behavior such as equilibrium abnormalities, rotational behavior, and vertical swimming, when exposed to phenytoin. Therefore, it is hypothesized that predator avoidance may be hindered. This study aimed to investigate the effects of phenytoin exposure-induced behavioral abnormalities in predator avoidance in Japanese medaka. The results showed that individuals with behavioral abnormalities had a reduced ability to avoid danger. Furthermore, the fish demonstrated a delayed recognition reaction to approaching predators. Additionally, predatory fish, such as silver pike characin (Ctenolucius hujeta), were more likely to prey upon abnormal individuals. In conclusion, the fish exposed to phenytoin demonstrated behavioral changes that increased its predation risk. This study is the first to determine the effects of behavioral abnormalities in Japanese medaka which was induced after phenytoin exposure on predator risk avoidance.2024年05月, Environmental toxicology and pharmacology, 108, 104474 - 104474, 英語, 国際誌[査読有り]研究論文（学術雑誌）Disruption of the thyroid hormone system by synthetic chemicals is gaining attention owing to its potential negative effects on organisms. In this study, the effects of the dio-inhibitor iopanoic acid (IOP) on the levels of thyroid hormone and related gene expression, swim bladder inflation, and swimming performance were investigated in Japanese medaka. Iopanoic acid exposure suppressed thyroid-stimulating hormone β (tshβ), tshβ-like, iodotyronin deiodinase 1 (dio1), and dio2 expression, and increased T4 and T3 levels. In addition, IOP exposure inhibited swim bladder inflation, reducing swimming performance. Although adverse outcome pathways of thyroid hormone disruption have been developed using zebrafish, no adverse outcome pathways have been developed using Japanese medaka. This study confirmed that IOP inhibits dio expression (a molecular initiating event), affects T3 and T4 levels (a key event), and reduces swim bladder inflation (a key event) and swimming performance (an adverse outcome) in Japanese medaka.2024年04月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 109930 - 109930, 英語, 国際誌[査読有り]研究論文（学術雑誌）Organophosphate esters (OPEs) have received considerable attention in environmental research due to their extensive production, wide-ranging applications, prevalent presence, potential for bioaccumulation, and associated ecological and health concerns. Low efficiency of OPE removal results in the effluents of wastewater treatment plants emerging as a significant contributor to OPE contamination. Their notable solubility and mobility give OPEs the potential to be transported to coastal ecosystems via river discharge and atmospheric deposition. Previous research has indicated that OPEs have been widely detected in the atmosphere and water bodies. Atmospheric deposition across air-water exchange is the main input route for OPEs into the environment and ecosystems. The main processes that contribute to air-water exchange is air-water diffusion, dry deposition, wet deposition, and the air-water volatilization process. The present minireview links together the source, occurrence, and exchange of OPEs in water and air, integrates the occurrence and profile data, and summarizes their air-water exchange in the environment.2024年04月, Chemosphere, 141874 - 141874, 英語, 国際誌[査読有り]研究論文（学術雑誌）Abstract Plastic pollution is considered a pervasive global environmental challenge. Colored microplastics are prevalent in aquatic environments and the gastrointestinal tracts of wild-captured fish and crustaceans. Fish are thought to employ color vision to detect microplastics, prompting our investigation into microplastic ingestion patterns in three marine fish species, Chrysiptera cyanea, Hypoatherina tsurugae, and Plotosus japonicus, and three freshwater fish species, Rhodeus ocellatus, Pseudorasbora parva, and Misgurnus anguillicaudatus. Microplastics in red, blue, yellow, green, and gray were introduced to these species, and their ingestion was observed over a 4 h period under light conditions. Additionally, as crustaceans play an important role in connecting producers (phytoplankton) and consumers (fish) in natural ecosystems, we assessed a freshwater crustacean, Neocaridina denticulata. The crustacean did not ingest microplastics, and only 14% of P. parva individuals ingested microplastics (a proportion lower than that observed in the other fish species). Notably, C. cyanea, P. japonicus, and R. ocellatus exhibited color preferences in microplastic ingestion, with C. cyanea favoring red, P. japonicus preferring blue and gray, and R. ocellatus favoring red and yellow. Conversely, H. tsurugae, P. parva, and M. anguillicaudatus did not exhibit such color preferences. These findings suggest that certain fish use color vision to recognize and selectively ingest microplastics, with color preference being species-specific. Overall, this study provides new insights into microplastic ingestion by fish, potentially informing future toxicological assessments of microplastics in marine and freshwater fish and crustaceans intendan consumption.Springer Science and Business Media LLC, 2024年02月, Discover Oceans, 1(1) (1)[査読有り]研究論文（学術雑誌）Phthalate and non-phthalate plasticizers are used in polymer materials, such as plastic and rubber. It has recently been found that diisobutyl adipate (DIBA), which is considered an environmentally safe non-phthalate plasticizer, potentially acts as a thyroid disruptor in fish. Here, we investigated the sexual hormone effects of DIBA based on the expression levels of genes that respond to endocrine disruption and sexual hormone activity in the livers and gonads, and on gonadal sexual differentiation in Japanese medaka. Compared with the control group, the mRNA expression of chgH, vtg1, vtg2, and esr1 was significantly suppressed in the livers of DIBA exposed XX individuals. Furthermore, the mRNA expression of gsdf was significantly upregulated and downregulated in the gonads of XX and XY individuals, respectively. The mRNA expressions of esr1 and esr2b were significantly suppressed by DIBA exposure in the gonads of both XX and XY individuals. These observations suggest that DIBA has potential androgenic activity in Japanese medaka. However, normal testes and ovaries were observed in respective XY and XX medaka after DIBA exposure; therefore, these results suggest that DIBA may have weak androgenic activity.2024年01月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 277, 109836 - 109836, 英語, 国際誌[査読有り]研究論文（学術雑誌）2024年, Pollutants, 4(1) (1), 117 - 135, 英語[査読有り]研究論文（学術雑誌）NPPs (Non-phthalate plasticizers) are used as alternative plasticizers to phthalate esters, but there is limited knowledge on environmental residues, and they have not been reported in Japan. A method to analyze NPPs in seawater using solid-phase extraction was developed, and the residual burden of Diisobutyl adipate (DIBA), Acetyl tributyl citrate (ATBC), Di-(2-ethylhexyl) adipate (DEHA), Di-(2-ethylhexyl) sebacate (DEHS) and Trioctyl trimellitate (TOTM) in seawater and sediment from the Osaka Bay was measured. Using an Oasis Max column and acetone as the eluting solvent, the recovery of the target substances in seawater is >68 %. In Osaka Bay, no NPPs were detected in seawater. On the other hand, ATBC and TOTM were detected in the sediment at 36-69 ng/g and 47-131 ng/g, respectively, from about half of the 14 sites, while DEHA and DEHS were detected at 83 ng/g and 181 ng/g, respectively, from only one site.2023年12月, Marine pollution bulletin, 199, 115947 - 115947, 英語, 国際誌[査読有り]研究論文（学術雑誌）Elsevier BV, 2023年12月, Regional Studies in Marine Science, 103343 - 103343[査読有り]研究論文（学術雑誌）Plasticizers containing phthalates have the potential to alter endocrine function in vertebrates. While non-phthalate plasticizers were previously considered to be environmentally friendly and safe, our research team discovered that bis-(2-ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC) disrupt thyroid hormones in Japanese medaka (Oryzias latipes). We assessed reproductive- and estrogen-responsive gene expression patterns in Japanese medaka to determine whether the phthalate plasticizers bis-(2-ethylhexyl) phthalate (DEHP, positive control) and the non-phthalate plasticizers DEHA and ATBC disrupt endocrine signaling. The results showed that the levels of choriogenin H (chgH) and vitellogenin (vtg) genes increased after exposure to DEHP and ATBC, suggesting that these plasticizers may have estrogenic activity. Exposure to DEHP and DEHA resulted in the upregulation of kisspeptin (kiss), gonadotropin-releasing hormone (gnrh), and follicle-stimulating hormone beta (fshβ) genes, suggesting that these plasticizers may interfere with reproductive function. To the best of our knowledge, this is the first study to demonstrate that the non-phthalate plasticizers DEHA and ATBC can disrupt reproduction-related hormonal activity in fish.2023年10月, Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering, 1 - 9, 英語, 国際誌[査読有り]研究論文（学術雑誌）The green-lipped mussel Perna viridis’ sensitive nature and characteristic as a benthos organism that filters the sediment in its environment make it one of the possible bioindicators for pollution in the aquatic ecosystem. The present study aimed to determine the percentages of total shell deformities in comparison to the past data in the coastal waters of Peninsular Malaysia. It was found that several types of discontinuous, continuous, and unexplained shell abnormalities contributed to the overall range of shell deformities of 15.8–87.5%, which was greater in comparison to that (0.0–36.8%). The present study showed that the highest overall proportion of shell abnormalities occurred in Teluk Jawa, whereas the lowest percentages were found in Kampung (Kg.) Pasir Puteh. The regulative mechanisms at the well-known polluted sites at Kg. Pasir Puteh could be the explanation. Further research should be conducted to determine the degree of heavy metal that may be the source of these malformations in the mussel shells.MDPI AG, 2023年09月, Pollutants, 3(3) (3), 406 - 418[査読有り]研究論文（学術雑誌）The present study aimed to investigate the effect of Foeniculum vulgare essential oil on the health of the common carp (Cyprinus carpio). A total of 120 healthy fish were provided with feed containing 200, 400, and 600 mg/kg of F. vulgare oil for 60 days. Findings revealed that the oral administration of 200 mg/kg of F. vulgare oil significantly increased final weight, weight gain, and specific growth rate compared to the control group (p < 0.05). Plasma biochemical enzyme levels remained unchanged in 200 and 400 mg/kg treatments, whereas they were found to be significantly increased in treatments with 600 mg/kg. Although no significant alterations in glucose, triglyceride, and cholesterol levels were observed, the treated groups exhibited significant increases in total protein, albumin, globulin, and creatinine levels. Results also indicated significantly decreasing levels of glutathione peroxidase, whereas superoxide dismutase activity increased. The gonadosomatic index showed notable improvement in the 200 and 400 mg/kg groups. Furthermore, plasma concentrations of estradiol and testosterone were significantly affected by doses of 400 and 200 mg/kg. Findings suggest that, following the administration of F. vulgare extract, the reproductive and general health of the fish appears to be improved. Nevertheless, it is recommended to supplement fish diets with up to 200 mg/kg of F. vulgare extract to improve their reproductive and general health. Concentrations above this limit can potentially cause harm.MDPI AG, 2023年08月, Water, 15(16) (16), 2978 - 2978[査読有り]研究論文（学術雑誌）The objective of the study was to provide an updated checklist of benthic marine organisms in Pantai Remis (Selangor) and Blue Lagoon (Negeri Sembilan) in November 2022. The research areas comprised a total of 26 species of marine benthic organisms, which were divided into 12 orders, 18 families, and 22 genera. Benthic macrophytes formed the largest group (11 species), followed by other benthic macrofauna (molluscs, with eight species). In addition, three coral species, two gastropods, and two crabs were also recorded. The findings revealed that both sites are fertile and suitable habitats for marine benthic organisms. The established checklist of benthic organisms can serve as an ongoing basis for future reference as part of our efforts to develop coastal marine ecosystem management and conservation on the west coast of Peninsular Malaysia. In summary, the checklist of benthic organisms provides the basic information that is much needed for the protection of coastal ecosystems.Universal Wiser Publisher Pte. Ltd, 2023年08月, Environmental Protection Research, 294 - 302[査読有り]研究論文（学術雑誌）Gastropods Faunus ater and bivalves Psammotaea elongata were sampled from the intertidal waters of Pantai Sri Tujuh, Tumpat (Kelantan), and their different soft tissues and shells were determined for Ni and Fe. The outcomes showed that the shells of the two species had significantly (P< 0.05) higher non-essential Ni levels than those in the different soft tissues. The contrary results were found in the essential Fe, where different soft tissues had significantly (P< 0.05) higher Fe concentrations than those in the shells of the two molluscs. This phenomenon could be due to the different essentiality of the two different groups of Ni and Fes between the different soft tissues and shells of molluscs. The present finding indicated the shells of P. elongata and F. ater were storage sites for Ni.MedCrave Group Kft., 2023年07月, International Journal of Hydrology, 7(3) (3), 137 - 141[査読有り]研究論文（学術雑誌）2023年07月, PhytoKeys, 229, 139 - 155, 英語[査読有り]研究論文（学術雑誌）Elsevier BV, 2023年05月, Environmental Toxicology and Pharmacology, 104151 - 104151[査読有り]研究論文（学術雑誌）Elsevier BV, 2023年05月, Aquatic Toxicology, 106553 - 106553[査読有り]研究論文（学術雑誌）Pyriproxyfen is an agricultural chemical pesticide that has been detected in the aquatic environment. This study aimed to clarify the effects of pyriproxyfen on the growth as well as thyroid hormone- and growth-related gene expression of zebrafish (Danio rerio) during its early life stage. Pyriproxyfen exhibited a lethal effect in a concentration-dependent manner: the lowest and no effect concentrations were 250.7 and 111.7 μg/L, respectively. These concentrations were considerably higher than the residual environmental concentrations, indicating the low risk of this pesticide when present at such concentrations. In the zebrafish group treated with 56.6 μg/L pyriproxyfen, thyroid hormone receptor β gene expression levels remained unchanged, whereas thyroid-stimulating hormone β subunit, iodtyronin deiodinase 2, and thyroid hormone receptor α gene expression levels significantly decreased compared with the control group expression levels. In zebrafish treated with 111.7 or 250.7 μg/L pyriproxyfen, iodtyronin deiodinase 1 gene expression levels significantly increased. These results indicate that pyriproxyfen disrupts thyroid hormone activity in zebrafish. Furthermore, pyriproxyfen exposure inhibited zebrafish growth; consequently, we examined the expression of growth hormone (gh) and insulin-like growth factor-I (igf-1), which are important for growth. Pyriproxyfen exposure suppressed gh expression; however, the igf-1 expression levels remained unchanged. Therefore, growth inhibition due to pyriproxyfen exposure was attributed to the suppression of gh expression.2023年04月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 109632 - 109632, 英語, 国際誌[査読有り]研究論文（学術雑誌）The previous assessment intends to support the inaugural International Mussel Watch program's use of marine mussels as biomonitors of potentially toxic metals in aquacultural areas has been considered of low novelty even though it is a necessary biomonitoring. When it is looked into the connections between Mussel Watch and Nexus seafood-water-energy, the questions can be raised up because there is apparently no such discussion in the literature. Therefore, the objective of this review is to discuss the connections between Mussel Watch for potentially toxic metals and Nexus seafood-water-energy, based on the topic reported in the literature separately. The current short review can act as a springboard for additional insights to offer fresh perspectives and original suggestions on using marine mussels more effectively in biomonitoring investigations in connections to Nexus seafood-water-energy. Nowadays, the biomonitoring by using Mussel Watch has remained effective and sustainable which further highlighted their importance in pollution monitoring. The likelihood of improved and wider-ranging molluscan uses in environmental monitoring in the future is almost inevitable. However, more research is still needed to address the rising demand in line with sustainable, attainable United Nation Sustainable Development Goals (‘‘Responsible consumption and production’’, and ‘Good Health and Well-beings’). This is surely a major player in the Nexus’s seafood in cycle with water and energy that should be addressed in future biomonitoring studies.SciRes Literature LLC, 2023年03月, Journal of Biomedical Research & Environmental Sciences, 4(3) (3), 317 - 320[査読有り]研究論文（学術雑誌）The biochemical effects of sublethal exposure to polyethylene microplastics (PEM) of 40–48 µm particle size and the flame retardant tetrabromobisphenol A (TBBPA), a plastic additive, on the freshwater shrimp Palaemonetes argentinus were assessed. Here, we postulate that the use of enzyme and thyroid hormones as biomarkers contributes to the knowledge of the effects of microplastics and plastic additives on freshwater crustaceans. To address this, we evaluated the activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), and carboxilesterase (CbE, using 1-naphthyl acetate (NA) as substrate) and levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) after shrimp were exposed (for 96 h) to these xenobiotics at environmentally realistic concentrations. The results showed that the mixture of both xenobiotics led to a decrease in AChE and GST activities and increased T4 levels. We suggest that physiological processes could be compromised in freshwater organisms when exposed to microplastics and TBBPA together, and this could ultimately affect upper levels of the food web.MDPI AG, 2023年03月, Biology, 12(3) (3), 391 - 391[査読有り]研究論文（学術雑誌）International Association of Advanced Materials, 2023年02月, Advanced Materials Letters, 14(1) (1)[査読有り]研究論文（学術雑誌）Plasticizer pollution of the water environment is one of the world's most serious environmental issues. Phthalate plasticizers can disrupt endocrine function in vertebrates. Therefore, this study analyzed thyroid-related, reproduction-related, and estrogen-responsive genes in Japanese medaka (Oryzias latipes) to determine whether nonphthalate diisobutyl adipate (DIBA) plasticizer could affect endocrine hormone activity or not. Developmental toxicity during fish embryogenesis was also evaluated. At a concentration of 11.57 mg/L, embryonic exposure to DIBA increased the mortality rate. While abnormal development, including body curvature, edema, and lack of swim bladder inflation, were observed at 3.54 and 11.57 mg/L DIBA. Growth inhibition and reduced swimming performance were also observed. In addition, DIBA exposure increased the levels of thyroid-stimulating hormone beta-subunit (tshβ) and deiodinase 1 (dio1) but decreased the levels of thyroid hormone receptor alpha (trα) and beta (trβ). These results suggest that DIBA has thyroid hormone-disrupting activities in fish. However, kisspeptin (kiss1 and kiss2), gonadotropin-releasing hormone (gnrh1), follicle-stimulating hormone beta (fshβ), luteinizing hormone beta (lhβ), choriogenin H (chgH), and vitellogenin (vtg1) expression did not change dose-dependently in response to DIBA exposure, whereas gnrh2 and vtg2 expression was elevated. These results indicate that DIBA has low estrogenic activity and does not disrupt the endocrine reproduction system in fish. Overall, this is the first report indicating that nonphthalate DIBA plasticizer is embryotoxic and disrupt thyroid hormone activity in fish.2023年01月, Journal of applied toxicology : JAT, 英語, 国際誌[査読有り]研究論文（学術雑誌）The present investigation focused on the toxicity test of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn), utilizing two groups of juvenile and adult apple snail Pomacea insularum (Gastropod, Thiaridae) with mortality as the endpoint. For the adult snails, the median lethal concentrations (LC50) values based on 48 and 72 h decreased in the following order: Cu < Ni < Pb < Cd < Zn. For the juvenile snails, the LC50 values based on 48 and 72 h decreased in the following order: Cu < Cd < Ni < Pb < Zn. The mussel was more susceptible to Cu than the other four metal exposures, although the juveniles were more sensitive than the adults because the former had lower LC50 values than the latter. This study provided essential baseline information for the five metal toxicities using P. insularum as a test organism, allowing comparisons of the acute sensitivity in this species to the five metals. In conclusion, the present study demonstrated that P. insularum was a sensitive biomonitor and model organism to assess heavy metal risk factors for severe heavy metal toxicities. A comparison of the LC50 values of these metals for this species with those for other freshwater gastropods revealed that P. insularum was equally sensitive to metals. Therefore, P. insularum can be recommended as a good biomonitor for the five metals in freshwater ecosystems.MDPI AG, 2023年01月, Applied Sciences, 13(2) (2), 1042 - 1042[査読有り]研究論文（学術雑誌）Thyroid-hormone-disrupting chemicals are increasingly attracting attention because of their potential harmful effects on animal health, including on fishes. Here, we investigated the effects of exposure to the thyroid-hormone-disrupting chemicals 6-propyl-2-thiouracil (PTU) and tetrabromobisphenol A (TBBPA) on swim bladder inflation, eye development, growth, swimming performance, and the expression of thyroid-related genes in Japanese medaka (Oryzias latipes). PTU exposure resulted in reductions in eye size, growth, and swim bladder inflation, and these effects led to poorer swimming performance. These phenotypic effects were accompanied by increased expression of the thyroid-stimulating hormone subunit beta (tshβ) paralog tshβ-like, but there were no significant changes in expression for tshβ, deiodinase 1 (dio1), deiodinase 2 (dio2), and thyroid hormone receptor alpha (trα) and beta (trβ). For PTU exposure, we identified the key event (swim bladder inflation reduction) and an adverse outcome (swimming performance reduction). No significant effects from TBBPA exposure were seen on swim bladder inflation, eye development, growth, or swimming performance. However, expression of tshβ-like and tshβ (significantly enhanced) and trα and trβ (significantly reduced) were affected by TBBPA exposure albeit not in dose-dependent manners. There were no effects of TBBPA on the expression of dio1 and dio2. We thus show that the two thyroid-hormone-disrupting chemicals PTU and TBBPA differ in their effect profiles with comparable effects on the studied phenotypes and thyroid-related gene expression to those reported in zebrafish.Elsevier BV, 2023年01月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 263, 109502 - 109502, 英語, 国際誌[査読有り]研究論文（学術雑誌）Japanese medaka is specified as a model fish in the OECD Test Guidelines. Recently, populations of Japanese medaka in Japan were divided into two species, the northern Oryzias sakaizumii and the southern O. latipes. Previously, we reported that induction concentrations for sex reversal by exposure to 17a-methyltestosterone differed significantly between these two species, indicating that they respond differently to endocrine-disrupting chemicals. In the present study, we examined the effects of exposure to two more endocrine-disrupting chemicals (bisphenol A and 17β-trenbolone) in O. sakaizumii, and compared the results to those previously reported for O. latipes. Both bisphenol A and 17β-trenbolone exposure induced testis-ova formation or sex reversal in O. sakaizumii. 17β-trenbolone exposure also increased gonadal soma-derived factor (gsdf) expression. Least-observed-effect concentrations for gonadal sex differentiation and gsdf expression were lower for O. latipes than for O. sakaizumii upon exposure to bisphenol A, and were lower for O. sakaizumii than for O. latipes upon exposure to 17β-trenbolone. These results demonstrate that O. sakaizumii and O. latipes respond differently to androgenic and estrogenic endocrine-disrupting chemicals. This article is protected by copyright. All rights reserved. Environ Toxicol Chem 2022;00:0-0. © 2022 SETAC.2022年12月, Environmental toxicology and chemistry, 英語, 国際誌[査読有り]研究論文（学術雑誌）Water pollution due to plasticizers is one of the most severe environmental problems worldwide. Phthalate plasticizers can act as endocrine disruptors in vertebrates. In this study, we investigated whether the non-phthalate bis(2-ethylhexyl) sebacate (DEHS) plasticizer can act as an endocrine disruptor by evaluating changes in the expression levels of thyroid hormone-related, reproduction-related, and estrogen-responsive genes of Japanese medaka (Oryzias latipes) exposed to the plasticizer. Following the exposure, the gene expression levels of thyroid-stimulating hormone subunit beta (tshβ), deiodinase 1 (dio1), and thyroid hormone receptor alpha (trα) did not change. Meanwhile, DEHS suppressed dio2 expression, did not induce swim bladder inflation, and eventually reduced the swimming performance of Japanese medaka. These findings indicate that DEHS can potentially disrupt the thyroid hormone-related gene expression and metabolism of these fish. However, exposure to DEHS did not induce changes in the gene expression levels of kisspeptin 1 (kiss1), gonadotropin-releasing hormone (gnrh), follicle-stimulating hormone beta (fshβ), luteinizing hormone beta (lhβ), choriogenin H (chgH), and vitellogenin (vtg) in a dose-dependent manner. This is the first report providing evidence that DEHS can disrupt thyroid hormone-related metabolism in fish.2022年12月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 109531 - 109531, 英語, 国際誌[査読有り]研究論文（学術雑誌）Bisphenol A (BPA) is an endocrine disruptor that is present in freshwater and marine environments. However, conclusive evidence for the toxicity of chronic BPA exposure to marine fishes remains lacking. Therefore, we investigated the influence of BPA on male marine medaka (Oryzias melastigma). BPA exposure induced formation of testis-ova at 2610 µg/L, and male-type anal fins became more female type in a concentration-dependent manner. Some males with female-type anal fins had normal testes, indicating that anal fin shape is more sensitive to BPA. Gonadal soma-derived factor (gsdf) expression decreased after BPA exposure in the 746 and 2610 µg/L exposure groups, although the changes were not statistically significant. Additionally, liver vitellogenin (vtg) expression increased in a dose-dependent manner and was significantly higher in all exposure groups. vtg and gsdf are likely to be useful biomarkers for the impact of estrogenic endocrine disrupters in O. melastigma.2022年11月, Environmental science and pollution research international, 英語, 国際誌[査読有り]研究論文（学術雑誌）Elsevier BV, 2022年11月, Chemosphere, 137141 - 137141[査読有り]研究論文（学術雑誌）Elsevier BV, 2022年11月, Journal of Hazardous Materials Advances, 8, 100199 - 100199[査読有り]研究論文（学術雑誌）2022年10月, Journal of Biomedical Research & Environmental Sciences, 3(19) (19), 1224 - 1228Zinc Concentrations in Different Parts of the Gastropod, Faunus ater, Collected from Intertidal Areas of Peninsular Malaysia[査読有り]Pollution of water bodies with plasticizers is a serious environmental problem worldwide. In this study, we investigated the effects of plasticizers bis-(2-ethylhexyl) phthalate (DEHP) and bis-(2-ethylhexyl) adipate (DEHA) in Japanese medaka (Oryzias latipes). DEHP significantly increased the expression of all the genes tested: thyroid stimulating hormone beta subunit (tshβ-like), tshβ, deiodinase 1 (dio1), deiodinase 2 (dio2), and thyroid hormone receptor alpha (trα) and beta (trβ). However, DEHA only significantly increased tshβ at 7.4 µg/L but significantly decreased dio2 expression at 25.8, 111.1, and 412.6 4 µg/L, while other genes were not significantly affected. Both chemicals reduced eye size and total body length, but did not affect embryo development, hatching time and rate, and swimming performance. DEHA alone affected swim bladder inflation and not DEHP. This is the first report that not only DEHP but also DEHA disrupt thyroid hormone activity in fish. DEHP contamination (13.2 μg/L) was detected in tap water from Kobe, Japan; thus, tap water itself may disrupt thyroid hormone activity in Japanese medaka. Importantly, the effective concentration of DEHP for thyroid hormone-related gene expression and growth was close to or lower than DEHP concentrations reported in surface water elsewhere, indicating that DEHP contamination is a serious aquatic pollution.2022年09月, Aquatic toxicology (Amsterdam, Netherlands), 252, 106312 - 106312, 英語, 国際誌[査読有り]研究論文（学術雑誌）Chemicals with androgenic or estrogenic activity induce the sex reversal and/or intersex condition in various teleost fish species. Previously, we reported that exposure to 17α-methyltestosterone, bisphenol A, or 4-nonylphenol induces changes in expression of gonadal soma-derived factor (gsdf) gene accompanied by disruption of gonadal differentiation in Japanese medaka (Oryzias latipes). These findings suggest that gsdf expression might be a useful biomarker for predicting potential of chemicals on gonadal differentiation. Here, we examined the gsdf expression in Japanese medaka exposed to chemicals with estrogenic or androgenic activity. Exposure to the androgenic steroid 17β-trenbolone at 0.5-22.1 μg/L induced ovotestis (presence of ovarian tissue with testicular tissue) development and female-to-male sex reversal in XX embryos, and exposure at 6.32 and 22.1 μg/L significantly increased gsdf expression in XX embryos compared with controls at developmental stage 38 (1 day before hatching). In the present study, no statistically significant difference in gsdf mRNA expression was observed by 17β-estradiol, 17α-ethinylestradiol, and 4-t-octylphenol exposure, which have estrogenic activity. In addition, anti-androgenic chemicals or chemicals without endocrine-disrupting activity did not induce changes in gsdf expression in XX nor XY embryos. Thus, an increase of gsdf expression after androgen exposure was observed in XX embryos. Together, these findings indicate that gsdf expression might be useful for predicting the adverse effect of chemicals on gonadal differentiation. This article is protected by copyright. All rights reserved.© 2022 SETAC.2022年05月, Environmental toxicology and chemistry, 英語, 国際誌[査読有り]研究論文（学術雑誌）We examined ingestion and retention rates of microplastics (MPs) by two freshwater (Japanese medaka and zebrafish) and two marine fish species (Indian medaka and clown anemonefish) to determine their color preferences and gastrointestinal-tract retention times. In our ingestion experiments, clown anemonefish ingested the most MP particles, followed by zebrafish, and then Japanese and Indian medaka. Next, we investigated color preferences among five MP colors. Red, yellow, and green MP were ingested at higher rates than grey and blue MPs for all tested fish species. To test whether these differences truly reflect a recognition of and preference for certain colors based on color vision, we investigated the preferences of clown anemonefish for MP colors under light and dark conditions. Under dark conditions, ingestion of MP particles was reduced, and color preferences were not observed. Finally, we assessed gastrointestinal-tract retention times for all four fish species. Some individuals retained MP particles in their gastrointestinal tracts for over 24h after ingestion. Our results show that fish rely on color vision to recognize and express preferences for certain MP colors. In addition, MP excretion times varied widely among individuals. Our results provide new insights into accidental MP ingestion by fishes.2022年04月, Environmental pollution (Barking, Essex : 1987), 119253 - 119253, 英語, 国際誌[査読有り]研究論文（学術雑誌）We compared the influence of thyroid hormone-disrupting chemicals (heptafluorobutanoic acid, PFBA and tris(1,3-dichloro-2-propyl) phosphate, TDCPP), and thyroid hormone (3,3',5-triiodo-L-thyronine, T3) on swim bladder inflation and thyroid hormone-related gene expression in Japanese medaka and zebrafish. The swim bladder of most larvae had inflated at 4 hours post hatching (hph) in Japanese medaka and at 48 hph in zebrafish in controls. In both fish species, the swim bladder inflation was inhibited in larvae exposed to PFBA (lowest observed effect concentration (LOEC) in medaka: 40 mg/L; in zebrafish: 80 mg/L), TDCPP (LOEC in medaka: 1 mg/L; in zebrafish: 0.5 mg/L), and T3 (no inhibition in Japanese medaka; LOEC in zebrafish: 7.5 μg/L). We also examined the influence of PFBA, TDCPP, and T3 on the expression of thyroid stimulating hormone subunit beta (tshβ) or thyroid hormone receptor alpha (trα) and beta (trβ). No changes were observed in the expression of genes after PFBA and TDCPP exposure; however, T3 exposure upregulated trα and trβ expression in both fish species. When the results were compared between Japanese medaka and zebrafish, swim bladder inflation in both species was found to be inhibited by exposure to thyroid hormone-disrupting chemicals. Our results show that inhibition of the swim bladder inflation at 4 hph in Japanese medaka and 48 hph in zebrafish is a potential indicator of thyroid hormone-disturbing activity of chemicals.2022年02月, Journal of applied toxicology : JAT, 42(8) (8), 1385 - 1395, 英語, 国際誌[査読有り]研究論文（学術雑誌）We investigated the lethal toxicity of Shibukuro and Tama river water near the inflow of Tamagawa hot-spring water in Akita Prefecture, Japan. We first measured metal concentrations in both rivers. We detected iron, arsenic, and aluminum; the concentrations of each tended to decrease from upstream to downstream. We next examined the influence of river water on zebrafish Danio rerio and water flea Daphnia magna. We observed lethal effects in both species, with Daphnia magna more sensitive to toxicity than Danio rerio. For both species, the toxic effects of river water decreased with increasing distance downstream from the inflow of hot-spring water. Our results show that the metals discharged from Tamagawa hot spring have a negative effect on aquatic organisms.2022年01月, Ecotoxicology (London, England), 英語, 国際誌[査読有り]研究論文（学術雑誌）In June 2016, the Ministry of the Environment of Japan announced a program "EXTEND2016" on the implementation of testing and assessment for endocrine active chemicals, consisting of a two-tiered strategy. The aim of the Tier 1 screening and the Tier 2 testing is to identify the impacts on the endocrine system and to characterize the adverse effects to aquatic animals by endocrine disrupting chemicals detected in the aquatic environment in Japan. For the consistent assessment of the effects on reproduction associated with estrogenic, anti-estrogenic, androgenic, and/or anti-androgenic activities of chemicals throughout Tier 1 screening to Tier 2 testing, a unified test species, Japanese medaka (Oryzias latipes), has been used. For Tier 1 screening, the in vivo Fish Short-Term Reproduction Assay (OECD test guideline No. 229) was conducted for 17 chemicals that were nominated based on the results of environmental monitoring, existing knowledge obtained from a literature survey, and positive results in reporter gene assays using the estrogen receptor of Japanese medaka. In the 17 assays using Japanese medaka, adverse effects on reproduction (i.e., reduction in fecundity and/or fertility) were suggested for 10 chemicals, and a significant increase of hepatic vitellogenin in males, indicating estrogenic (estrogen receptor agonistic) potency, was found for eight chemicals at the concentrations in which no overt toxicity was observed. Based on these results, and the frequency and the concentrations detected in the Japanese environment, estrone, 4-nonylphenol (branched isomers), 4-tert-octylphenol, triphenyl phosphate, and bisphenol A were considered as high priority candidate substances for the Tier 2 testing.2021年11月, Journal of applied toxicology : JAT, 42(5) (5), 750 - 777, 英語, 国際誌[査読有り]研究論文（学術雑誌）To determine whether the marine medaka Oryzias melastigma is a suitable model organism for in vivo acute toxicity bioassay in seawater, we first determined whether there were differences in the concentrations of chemicals that were toxic to marine medaka (O. melastigma) and freshwater medaka (O. latipes). We performed in vivo acute toxicity bioassay with 3-chloroaniline, triclosan, 3,4-dichloroaniline, fenitrothion, and pyriproxyfen on larvae of both species. Although the concentrations of 3-chloroaniline and fenitrothion that were lethal to the larvae were identical for both species, the toxic concentrations of triclosan, 3,4-dichloroaniline, and pyriproxyfen were lower for O. melastigma than for O. latipes. We then used an in vivo acute toxicity bioassay to monitor the quality of coastal seawater in Akita, Japan. No lethal effects were observed in the harbor and canal in 2019. O. melastigma could be used to monitor the quality of seawater with salinities in the range 2-25. Our findings suggest that O. melastigma can be used as the test fish for in vivo acute toxicity bioassay intended for water quality monitoring.2021年10月, Environmental monitoring and assessment, 193(11) (11), 725 - 725, 英語, 国際誌[査読有り]研究論文（学術雑誌）To determine whether the marine medaka Oryzias melastigma is a suitable model organism for evaluating the effects of environmental chemicals on marine teleosts, we examined the effect of salinity on physiological development and zinc toxicity. Growth as measured by total body length was significantly lower in fresh water compared to brackish water. Reproductive success was also significantly reduced in fresh water, although we observed cells in the pituitary producing gonadotropins such as Gpa (common glycoprotein hormone α), Fshb (follicle stimulating hormone β), and Lhb (luteinizing hormone β) at all salinities. These results indicate that O. melastigma is adaptable to various salinities from fresh to seawater, and brackish water is best for physiological processes including growth performance and reproduction. When zinc was dissolved in saltwater, a white precipitate formed immediately, and the dissolved concentration decreased in the supernatant and increased at precipitate. We performed zinc toxicity tests on early life stage and adult stage in fresh water, brackish water, and seawater. Among adults, the lowest observed effect concentration for mortality in freshwater (15.3 mg/L) was lower than in brackish water (>48 mg/L) or seawater (>48 mg/L). Similarly, among embryos and larvae, the lowest observed effect concentration for mortality in freshwater (4.8 mg/L) was lower than in brackish water (48 mg/L) or seawater (48 mg/L). These results highlight the importance of using marine organisms to evaluate the ecological effects of marine pollutants.2021年06月, Ecotoxicology (London, England), 英語, 国際誌[査読有り]研究論文（学術雑誌）In the present study, we assessed the negative effects of triphenyltin (TPT) on zebrafish (Danio rerio) by exposing embryos and early-stage larvae to various concentrations of TPT from 2 h after fertilization (haf) until 30 days after hatching (dah). Whether test groups were fed or fasted during ecotoxicity studies using fish models has varied historically, and whether this experimental condition influences test results is unknown. Here, we confirmed that the lethal concentration of TPT to embryo and early-stage larvae (i.e., 3 dah or younger) showed in fed (lowest observed effect concentration (LOEC); 6.34 μg/L) and fasted (LOEC; 6.84 μg/L) groups. In addition, 84% and 100% of the larvae in the 2.95 and 6.64 μg/L exposure groups, respectively, had uninflated swim bladders; all affected larvae died within 9 dah. This finding suggests that morphologic abnormalities in early larval zebrafish are useful as endpoints for predicting the lethality of chemical substances after hatching. We then assessed the expression of several genes in the thyroid hormone pathway, which regulates swim bladder development in many fish species, including zebrafish. Larvae exposed to 6.64 μg/L TPT showed significant increases in the mRNA expression levels of thyroid hormone receptor α (trα) and trβ but not of thyroid stimulating hormone β subunit. These findings suggest that TPT disrupts the thyroid system in zebrafish.2020年12月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 242, 108948 - 108948, 英語, 国際誌[査読有り]研究論文（学術雑誌）The branched isomer mixture 4-nonylphenol (4-NP) has been used worldwide as a surfactant, and can have endocrine-disrupting effects on aquatic organisms. For instance, 4-NP induces the formation of testis-ova (i.e., testicular and ovarian tissue in the same gonad) or male to female sex reversal of various teleost fishes. Recently, our group revealed that altered gsdf gene expression is associated with disruption of gonadal differentiation in Japanese medaka (Oryzias latipes) embryos exposed to methyltestosterone or bisphenol A, suggesting that gsdf might be useful as a biomarker for predicting the impact of endocrine-disrupting chemicals (EDCs) on gonadal differentiation. Here, we used 4-NP to examine further whether gsdf expression at the embryo stage is useful for predicting EDC impact on gonadal sex differentiation. When fertilized medaka eggs were exposed to 32 or 100 μg/L 4-NP, testis-ova in genetic males and sex reversal from genetic male to phenotypic female were observed. At stage 38 (just before hatching), 4-NP exposure at 1-100 μg/L did not affect gsdf expression in XX embryos compared with the nontreated control; however, in XY embryos, the gsdf expression in the 100 μg/L-exposed group was significantly lower than that in the controls. The 4-NP concentration at which gsdf expression was suppressed was equal to that at which testis-ova and sex reversal were induced. These results indicate that expression of the gsdf gene at the embryonic stage in medaka is a useful biomarker for predicting the impact of EDCs on sexual differentiation.2020年08月, Journal of applied toxicology : JAT, 英語, 国際誌[査読有り]研究論文（学術雑誌）2020年06月, Biodiversity: Research and Conservation, 57(1), 1 - 12Nitzschia taikiensis sp. nov. (Bacillariophyta) – a new brackish diatom from the Toberi River marsh in the eastern Hokkaido, Japan.[査読有り]Bisphenol A (BPA), a very important raw material in the plastics industry, is an endocrine-disrupting chemical in teleost fish. Although BPA induces testis-ova and sex reversal in teleost fish species, the molecular mechanism remains unclear. We evaluated the effects of BPA (measured concentrations: 45, 92, 326, 1030 and 3406 μg/L) on Japanese medaka (Oryzias latipes) using OECD TG234 (2011, Fish Sexual Development Test, OECD Guidelines for the Testing of Chemicals, Section 2). BPA at 1030 and 3406 μg/L induced testis-ova and sex reversal with female-type secondary sexual characteristics in XY males at 30 and 60 days posthatching (dph). Then we examined the BPA effect on the expression of sex differentiation genes related to the testis-ova and sex reversal in XY medaka. BPA exposure (1030 and 3406 μg/L) suppressed gsdf mRNA expression and increased cyp19a1a mRNA expression in XY individuals at stage 38 and 30 dph, although foxl2 mRNA expression showed no change. Interestingly, the concentration of BPA that suppressed gsdf mRNA expression at the larval stage was consistent with that needed to induce testis-ova and sex reversal. These results suggest that the gsdf gene at the embryonic stage can be used as a useful biomarker for predicting the impact of estrogenic endocrine-disrupting chemicals on sexual differentiation in Japanese medaka.2020年06月, Journal of applied toxicology : JAT, 40(6) (6), 804 - 814, 英語, 国際誌[査読有り]研究論文（学術雑誌）2019年12月, Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 108684[査読有り]2019年09月, Bulletin of Environmental Contamination and Toxicology, 103(3) (3), 411 - 415[査読有り]研究論文（学術雑誌）Diclofenac sodium, a non-steroidal anti-inflammatory drug widely used in both human and veterinary medicine, has been detected in aquatic environments; therefore, its ecotoxicological effects on aquatic organisms need to be clarified. Recently, toxicity testing using zebrafish (Danio rerio) embryos has been recommended from the point of view of animal welfare; therefore, we investigated the suitability of using sub-lethal endpoints observed during embryogenesis for predicting lethal effects in early life stage zebrafish exposed to diclofenac sodium. After exposure to diclofenac sodium (0.4-7.0 mg/L) from 2 hours post-fertilization to 30 days post-hatching, abnormal embryogenesis, characterized by the presence of edema and body curvature, was observed in the 7.0 mg/L exposure group but not in any other groups including controls. The body curvature was found to be the result of abnormal development of the spine. All abnormal embryos hatched without delay, but died within 1 week after hatching, suggesting that the combination of the sub-lethal endpoints of edema and abnormal development of the spine during embryogenesis may predict lethal effects in early life stage zebrafish exposed to diclofenac sodium. Further investigations to verify these findings are needed. The value of the no observed effect concentrations for the embryogenesis, survival and growth endpoints were 3.5, 1.8 and >3.5 mg/L, respectively.2019年04月, Journal of applied toxicology : JAT, 39(4) (4), 622 - 629, 英語, 国際誌[査読有り]研究論文（学術雑誌）The commercial use of metals such as copper, lead, and zinc has markedly increased in recent years, resulting in increased interest in deep-sea mining of seafloor hydrothermal sulfide deposits. However, the full extent of the impact of deep-sea mining at hydrothermal field deposits on the environment remains unclear. In addition to impacting the deep sea, the leaching of heavy metals from extracted sulfide mineral may also affect the upper ocean zones as the sulfide rock is retrieved from the seafloor. Here, we used a delayed fluorescence-based bioassay using the marine cyanobacterium Cyanobium sp. NIES-981 to evaluate the toxicity of three sulfide core samples obtained from three drill holes at the Izena Hole, middle Okinawa Trough, East China Sea. Leaches from two of the cores contained high concentrations of zinc and lead, and they markedly inhibited delayed fluorescence in Cyanobium sp. NIES-981 compared with control. By examining the toxicity of artificial mixed-metal solutions with metal compositions similar to those of the leaches, we confirmed that this inhibition was a result of high zinc and lead concentrations into the leaches. In addition, we conclude that this delayed fluorescence-based bioassay is a viable method for use by deep-sea mining operations because it is quicker and requires less laboratory space and equipment than the standard assay.2018年12月, Ecotoxicology (London, England), 27(10) (10), 1303 - 1309, 英語, 国際誌[査読有り]研究論文（学術雑誌）The lethal effects of chemicals is a serious concern to the protection of ecosystems, and the OECD TG 212 was established to estimate the lethal and sublethal effects on embryo and sac-fry stages of fish. It is still unclear, however, whether this test can effectively estimate the impacts of chemicals using marine fish. Therefore, this study aimed to use a recognized testing method on the marine fish Oryzias javanicus, and to assess differences in response to organotin compounds between a freshwater congener (Oryzias latipes) and O. javanicus. The lowest observed effect concentration (LOEC) of triphenyltin for lethal effect was the same in both species. The LOEC of tributyltin for lethal and sublethal effects were the same in both species. Our results provide the first evidence that O. javanicus and O. latipes are similarly affected by organotin compounds, suggesting that O. javanicus is a good model marine fish for the ecotoxicological assessment of chemicals.2018年09月, Bulletin of environmental contamination and toxicology, 101(3) (3), 344 - 348, 英語, 国際誌[査読有り]研究論文（学術雑誌）Tributyltin, an organotin compound, was used worldwide as an antifouling agent in aquatic environments and there has been much concern about the toxicological and ecotoxicological properties of organotin compounds. Even though it has been prohibited worldwide, tributyltin is still detected at low concentrations in aquatic environments. Here we investigated the effects of tributyltin on the early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes). In adults, exposure to tributyltin at 3.82 μg/L suppressed fecundity and fertility and increased mortality. At 10.48 μg/L all medaka died by the sixth day of exposure. Exposure to tributyltin during early life-stages induced no significant differences in mortality or embryonic development, but growth was suppressed in groups exposed to 0.13 and 0.68 μg/L. Furthermore, there was no abnormal gonadal development in Japanese medaka exposed to tributyltin. These results provide evidence of the negative effects of tributyltin on reproduction in a teleost fish. Tributyltin did not affect gonadal sex differentiation in Japanese medaka, but fecundity and fertility were suppressed, although it is not clear whether this suppression resulted from the endocrine-disrupting action of tributyltin or its toxicity.2018年07月, Chemosphere, 203, 418 - 425, 英語, 国際誌[査読有り]研究論文（学術雑誌）Triclosan has been shown to have endocrine-disrupting effects in aquatic organisms. In 2016, the US Food and Drug Administration banned the use of triclosan in consumer soaps. Before the ban, triclosan was reported at low concentrations in the aquatic environment, although the effect of triclosan on reproduction in teleost fish species is yet to be clarified. Here we investigated the effects of triclosan on embryo development and reproduction, and during the early life stage, in Japanese medaka (Oryzias latipes) by using Organisation for Economic Co-operation and Development tests 229, 212 and 210, with minor modifications. In adult medaka, exposure to 345.7 μg l-1 suppressed fecundity and increased mortality but had no effect on fertility. Exposure to 174.1 or 345.7 μg l-1 increased liver vitellogenin concentration in females but decreased liver vitellogenin concentration in males. With triclosan exposure, mortality was increased dose dependently during the embryonic and early larval stages, and a particularly steep increase in mortality was observed soon after hatching. The lowest observed effect concentrations of triclosan in Japanese medaka obtained in the present study (mortality [embryonic and larval stages, 276.3 μg l-1 ; early life stage, 134.4 μg l-1 ; adult stage, 174.1 μg l-1 ], growth [134.4 μg l-1 ], vitellogenin [174.1 μg l-1 ], fecundity [345.7 μg l-1 ] and fertility [>345.7 μg l-1 ]) were at least 55 times (compared with the USA) and up to 13 400 times (compared with Germany) greater than the detected triclosan levels in the aquatic environment. These results suggest that triclosan may not be affecting fish populations in the aquatic environment.2018年04月, Journal of applied toxicology : JAT, 38(4) (4), 544 - 551, 英語, 国際誌[査読有り]研究論文（学術雑誌）2017年12月, ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 36(12) (12), 3254 - 3266, 英語[査読有り]研究論文（学術雑誌）2017年11月, AQUATIC TOXICOLOGY, 192, 16 - 23, 英語[査読有り]研究論文（学術雑誌）2017年10月, AQUATIC TOXICOLOGY, 191, 209 - 218, 英語[査読有り]研究論文（学術雑誌）2017年10月, JOURNAL OF APPLIED TOXICOLOGY, 37(10) (10), 1245 - 1253, 英語[査読有り]研究論文（学術雑誌）2017年07月, JOURNAL OF APPLIED TOXICOLOGY, 37(7) (7), 836 - 841, 英語[査読有り]研究論文（学術雑誌）2017年05月, CHEMOSPHERE, 174, 1 - 7, 英語[査読有り]研究論文（学術雑誌）2017年03月, JOURNAL OF APPLIED TOXICOLOGY, 37(3) (3), 339 - 346, 英語[査読有り]研究論文（学術雑誌）2017年02月, PLOS ONE, 12(2) (2), e0171259, 英語[査読有り]研究論文（学術雑誌）2016年12月, ECOTOXICOLOGY, 25(10) (10), 1751 - 1758, 英語[査読有り]研究論文（学術雑誌）2016年11月, MOLECULAR AND CELLULAR ENDOCRINOLOGY, 436(C) (C), 141 - 149, 英語[査読有り]研究論文（学術雑誌）2015年07月, JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY, 323(6) (6), 392 - 398, 英語[査読有り]研究論文（学術雑誌）2015年02月, JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY, 323(2) (2), 74 - 79, 英語[査読有り]研究論文（学術雑誌）2014年10月, JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY, 321(8) (8), 472 - 477, 英語[査読有り]研究論文（学術雑誌）2014年08月, GENERAL AND COMPARATIVE ENDOCRINOLOGY, 204, 173 - 180, 英語[査読有り]研究論文（学術雑誌）Biogeographical Society of Japan, 2013年, Biogegraphy, 15, 55 - 62, 英語Gonadal histology of wild giant mottled eel, Anguilla marmorata in Okinawa, Japan[査読有り]
■ MISC- 2023年, 日本水環境学会シンポジウム講演集, 26th大阪湾をモデルケースにしたマイクロプラスチックの生態リスク評価
- 2023年, 日本水環境学会年会講演集, 57th海水中の非フタル酸可塑剤の分析方法の検討
- 2023年, 日本水環境学会年会講演集, 57th生分解性プラスチックの天然海水中での分解性及び生態毒性評価
- 2023年, 日本水環境学会年会講演集, 57th大阪湾における海表面マイクロ層の微粒子の残留
- 2023年, マリンエンジニアリング学術講演会講演論文集, 93rd大阪湾の海表面マイクロ層の重金属を含む微粒子
- 2022年, Diatom, 38Epithemia adnara,E.gibba及びE.sorexの生育可能な塩分範囲
- 2022年, 日本水環境学会年会講演集, 56th褐藻ワカメを用いた化学物質の有害性評価試験法の開発
- 2022年, ソルト・サイエンス研究財団助成研究報告集 1 理工学編, 2020バイオアッセイを用いた沿岸海水中の環境汚染物質の検出および高精度化インドメダカを用いた生態毒生試験
- 2021年, 環境化学討論会要旨集(CD-ROM), 29thマイクロカプセルに内包された化学物質の環境リスクについて
- 2021年, Endocrine Disrupter News Letter (Web), 23(2) (2)レゾルシノールの甲状腺系への内分泌かく乱作用
- 2021年, ソルト・サイエンス研究財団助成研究報告集 1 理工学編, 2019沿岸海水中の環境汚染物質を検出する新たなスクリーニング法の開発 インドメダカを用いたバイオアッセイ
- 2019年, 日本水環境学会年会講演集, 53rd秋田市旭川流域の都市排水路における流出水中のPPCPsの経月変化
- 2018年, 日本気象学会大会講演予稿集, (114) (114), 409, 日本語秋田県生保内地方の局地風に関する研究
- 秋田県立大学（地域連携・研究推進センター）, 2018年, 秋田県立大学ウェブジャーナルB(研究成果部門)(Web), 5(5) (5), 59 - 72, 日本語産業廃棄物処分場における有害物質の適正管理およびリスク削減対策に関する基盤的研究
- 2017年, 環境化学討論会要旨集(CD-ROM), 26th, ROMBUNNO.1C‐01, 日本語第一回生態影響試験チャレンジテスト(国立環境研究所の結果)
- 2017年, 環境化学討論会要旨集(CD-ROM), 26th, ROMBUNNO.1C‐05, 日本語ノニルフェノールの延長“メダカ拡張一世代繁殖試験“結果
- 2017年, 日本内分泌かく乱化学物質学会研究発表会要旨集, 20th, 60, 日本語メダカ胚への性ホルモン曝露による性転換誘導と性分化関連遺伝子の発現
- 2016年, 環境化学討論会要旨集(CD-ROM), 25th, ROMBUNNO.1A‐01, 日本語メダカ拡張一世代繁殖試験を用いたノニルフェノールの多世代影響評価
- 2016年, 環境化学討論会要旨集(CD-ROM), 25th, ROMBUNNO.1A‐02, 日本語メダカを用いた抗アンドロゲン試験法の開発~フェニトロチオン~
- 2014年, 日本動物学会大会予稿集, 85th, 153, 日本語メダカにおけるXX性転換誘起機構
- 2013年, 日本動物学会大会予稿集, 84th, 170, 日本語メダカのGTH産生細胞分化過程でみられる集団差
- 2012年, 養殖, 49(4) (4), 86 - 88, 日本語新しい養殖形態への挑戦 流氷の町の地産地消に貢献したオーガニック蓄養システム クロガシラカレイ,シマゾイの畜養に成功
- 2012年, 日本動物学会大会予稿集, 83rd, 115, 日本語メダカの生殖腺分化・発達過程におけるGTH産生細胞の動態
- 2011年, 日本比較内分泌学会大会及びシンポジウムプログラム・講演要旨, 36th, 38, 日本語メダカの生殖腺分化・発達過程におけるGTH産生細胞の動態
- 2011年, 日本動物学会大会予稿集, 82nd, 96, 日本語絶滅危惧種ニホンザリガニCambaroides japonicus精巣の周年変化
- 2011年, 日本動物学会大会予稿集, 82nd, 137, 日本語北海道固有絶滅危惧種の孵化に及ぼす水温とpHの影響
- 2011年, 日本動物学会大会予稿集, 82nd, 96, 日本語絶滅危惧種ニホンザリガニCambaroides japonicus卵巣の周年変化
- 2010年, 日本動物学会大会予稿集, 81st, 94, 日本語魚類性分化過程における組織構築と性的可塑性
- 2010年, 日本水産学会大会講演要旨集, 2010, 101, 日本語オホーツク産魚類のオーガニック蓄養の可能性
- 2010年, 日本魚類学会年会講演要旨, 43rd, 36, 日本語北海道固有希少淡水魚の種苗生産についての試み
■ 共同研究・競争的資金等の研究課題- 日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 2024年04月01日 - 2028年03月31日化学物質の有害性を予測・毒性評価する新規バイオマーカーの探索とその応用
- 独立行政法人環境再生保全機構 環境研究総合推進費, 2023年04月 - 2026年03月, 研究代表者メダカを用いた甲状腺ホルモンかく乱物質の検出試験法の開発
- 日化協, LRI, 2023年03月 - 2026年02月閉鎖性海域 大阪湾を モデルケースにしたMPの生態リスク評価
- 日本学術振興会, 科学研究費助成事業 基盤研究(A), 基盤研究(A), 愛媛大学, 2019年04月01日 - 2024年03月31日マイクロカプセルを介した化学物質の新たな環境動態の解明と評価マイクロカプセル（MC）とは、芯材に様々な化学物質を封入した微細な粒子状物質を指す。カプセルに封入された化学物質は、化学物質本来の化学構造から推定される環境動態とは異なる動きを示し、欧州ではマイクロプラスチックと同等に規制対象となっている。本年度はカプセルの水中挙動や生体内動態をより正確に把握するために、市販のMC製品/製剤からカプセルのみを精製することを試みたが、フィルターろ過や遠心分離によってカプセルだけを抽出することが夾雑物（界面活性剤、安定化剤など）や比重が近いなどの影響で難しかった。そこで、当初の計画に従いMCの合成を試みた。 マイクロカプセルの生態毒性を調べることを目的としているため、ミジンコやメダカが摂食できる大きさのカプセルを作成することが必須であったため、アルギン酸などによる比較的大型のカプセルではなく、小さい粒子を形成できてかつ生態影響が少ないと思われる基材として、生分解性を有するキャリア粒子として，乳酸・グリコール酸共重合体（PLGA）を基材とした。外殻にはやはり生態影響の少ないPVA（ポリビニルアルコール）を選び、MC合成装置を用いて、2剤の界面張力を応用したカプセルの合成方法を検討した。 2剤の濃度、流速、送液圧力、流路径などについての検討を行い、直径20～50μmのカプセルの合成に成功した。ただし、PLGA内部に薬剤（農薬または発色剤）を混合したところ、界面張力が変化するため、更なる条件検討が必要になっている。 カプセル合成に使用しているMC合成装置が海外製のため、その交換部品の入手がコロナの影響で輸入が難しく、代替品の検討などを行ったが、代替品ではうまくいかなかった。そのため一時期合成に着手できずに計画の進捗が遅れてしまった。現在部品の一部は入手でき合成できるようになったが、今後納期が未定の部品もあるため工夫して研究を継続している。
- 公益財団法人 鉄鋼環境基金, 第43回（2022年度）環境助成研究, 2022年11月 - 2023年10月重金属類が海域・淡水域に生息する魚類に 与える生体影響の違い
- 公益財団法人クリタ水・環境科学振興財団, 国内研究助成, 2021年10月 - 2022年09月海産甲殻類アミ類を用いた新たな慢性毒性試験法の開発に向けた研究
- 日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 秋田県立大学, 2019年04月01日 - 2022年03月31日化学物質の有害性を予測する新規バイオマーカーの探索とその応用本研究では内分泌かく乱作用を示す化学物質を検出するための新規バイオマーカー遺伝子を調べた。その結果、女性ホルモン作用を示す化学物質をばく露した場合はXY個体のGsdf遺伝子の発現が抑制された。一方で、男性ホルモン作用を示す化学物質をばく露した場合はXX個体のGsdf遺伝子の発現が誘導された。性ホルモン作用を示さない内分泌かく乱化学物質や抗男性ホルモン作用を示す化学物質、一般化学物質をばく露した場合はXX個体、XY個体共にGsdf遺伝子の発現に変化は認められなかった。 以上のことから、Gsdf遺伝子は性ホルモン作用を示す内分泌かく乱化学物質の検出に有効な遺伝子マーカーであることが考えられた。
- 独立行政法人環境再生保全機構, 環境研究総合推進費, 2019年04月 - 2022年03月, 研究代表者化学物質の内分泌かく乱作用を予測・検出する新たなスクリーニング法の開発競争的資金
- 公益財団法人クリタ水・環境科学振興財団 国内研究助成, 2020年10月 - 2021年09月海洋漂流プラスチックから検出される有害化学物質が魚類に与える生態影響の解明
- 公益財団法人 鉄鋼環境基金, 第40回（2019年度）環境助成研究, 2019年11月 - 2020年10月, 研究代表者胚発生異常の「有無」を指標とした新たな生態毒性試験法の開発（継続）競争的資金
- 日本学術振興会, 科学研究費助成事業 若手研究(B), 若手研究(B), 秋田県立大学, 2017年04月01日 - 2020年03月31日新たな生態毒性試験法の開発 ～生態毒性学と分子生物学の融合～本研究では、男性ホルモン作用のある化学物質のばく露によって魚類の「胚期」にその発現が誘導され、かつ、性決定遺伝子カスケードであるGsdf遺伝子を指標とすることで、化学物質の「性別」への影響を予測する、高解像度かつ簡便な新たな生態毒性試験法の開発を目的とする。初年度は、従来の生態毒性試験法を用いてメチルテストステロン（男性ホルモン）がメダカの性別に影響する濃度を明らかにするため、メダカを用いた魚類性発達試験（OECD TG No. 234）を行った。これまでの先行研究から試験濃度は、対照区、32、100、320、1000、3200 ng/Lに設定した。試験期間中の死亡率について検討した結果、全ての濃度区で対照区を比べて有意な死亡率の増加は認められなかった。次に、生殖腺の組織学的観察を行い、卵精巣や性転換（遺伝的メス→機能的オス）の発生の有無について検討した結果、32 ng/L濃度区においても全ての個体が遺伝的メスから機能的オスへと性転換していた。対照区では、異常な生殖腺を有していた個体は認められなかった。以上の結果から、メチルテストステロンは32 ng/Lという非常に低濃度でもメダカの性別に影響を与えることが明らかとなった。
- 公益財団法人 ソルト・サイエンス研究財団, 2019年度研究助成, 2019年04月 - 2020年03月, 研究代表者沿岸海水中の環境汚染物質を検出する新たなスクリーニ ング法の開発競争的資金
- 公益財団法人 鉄鋼環境基金, 第39回（2018年度）環境助成研究, 2018年11月 - 2019年10月, 研究代表者胚発生異常の「有無」を指標とした新たな生態毒性試験法の開発競争的資金
- 公益財団法人クリタ水・環境科学振興財団, 国内研究助成（継続）, 2018年10月 - 2019年09月, 研究代表者海産魚類ジャワメダカを用いた化学物質の致死・亜致死影響を評価する生態毒性試験法の確立競争的資金
- 一般財団法人化学物質評価研究機構, 平成30年度CERI公募型研究助成, 2018年07月 - 2019年03月, 研究代表者汽水・海産メダカを用いた新たな生態毒性試験法の開発に向けた基盤的研究競争的資金
- 公益財団法人クリタ水・環境科学振興財団, 国内研究助成, 2017年10月 - 2018年09月, 研究代表者海産生物を用いた新たな生態毒性試験法の開発競争的資金
- 公益財団法人 ソルト・サイエンス研究財団 2020年度研究助成バイオアッセイを用いた沿岸海水中の環境汚染物質の検出および高精度化
研究シーズ
■ 研究シーズ- 水環境における有害化学物質の生体影響シーズカテゴリ：環境・農学, 自然科学一般研究キーワード：魚類, 性分化・性転換, 生態毒性, 環境ホルモン研究の背景と目的：科学技術の発展は、化学産業を発展させるとともに、人類に物質的に豊かで便利な生活をもたらしてきました。化学物質は、食品や農薬、医薬品、化粧品などあらゆる所で使用されており、私たちの生活に必要不可欠です。その反面で化学物質の流出汚染など、人類の生活活動による自然環境・生態系の破壊等、様々な環境問題をもたらしてきたことも事実です。そこで、有害化学物質の生物影響と生態リスク評価に関する研究を行っています。研究内容：淡水・海産メダカやゼブラフィッシュ、カクレクマノミなど、様々な魚類を用いて、化学物質が生物に与える影響について調べています。 化学物質の生物影響については、生態毒性学・分子生物学的手法を用いることで、遺伝子レベルから個体レベルまで調べています。期待される効果や応用分野：期待される効果や応用分野は、主に化学物質の生態影響試験を行う省庁や企業（環境コンサル）になります。