研究者紹介システム

坂本 克彦
サカモト カツヒコ
バイオシグナル総合研究センター
教授
農学関係
Last Updated :2024/01/31

研究者情報

所属

  • 【主配置】

    バイオシグナル総合研究センター
  • 【配置】

    大学院農学研究科 生命機能科学専攻

学位

  • 博士(理学), 横浜市立大学

授業科目

ジャンル

  • 環境・交通 / 農業

コメントテーマ

  • 昆虫
  • チョウ目昆虫幼虫の農薬感受性リズム

研究活動

研究分野

  • ライフサイエンス / 動物生理化学、生理学、行動学

論文

  • Asuka MATSUI, Makoto TOKUSHIGE, Akira MIZOGUCHI, Kengo KANAMARU, Katsuhiko SAKAMOTO, Yuichi UNO, Tomohide UNO

    Biology Centre, AS CR, 2023年03月29日, European Journal of Entomology, 120, 93 - 104, 英語

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    研究論文(学術雑誌)

  • Takako Nishi, Katsuhiko Sakamoto, Ryota Matsuo

    Elsevier BV, 2022年12月, Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 274, 111298 - 111298

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    研究論文(学術雑誌)

  • Ryota Matsuo, Sanae Kotoh, Kiyotaka Takishita, Katsuhiko Sakamoto, Tatsuya Uebi, Mamiko Ozaki, Yuko Matsuo, Takako Nishi

    University of Chicago Press, 2022年12月01日, The Biological Bulletin, 243 (3), 339 - 352

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    研究論文(学術雑誌)

  • Yuichi EGI, Katsuhiko SAKAMOTO

    Biology Centre, AS CR, 2022年11月07日, European Journal of Entomology, 119, 405 - 412

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    研究論文(学術雑誌)

  • Mako Sasao, Tomohide Uno, Risa Kitagawa, Asuka Matsui, Fumika Toryu, Akira Mizoguchi, Kengo Kanamaru, Katsuhiko Sakamoto, Yuichi Uno

    Springer Science and Business Media LLC, 2022年09月21日, Histochemistry and Cell Biology, 159 (2), 199 - 208

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    研究論文(学術雑誌)

  • Silkworm larvae (Bombyx mori) can learn cues associated with finding food.

    Tomohisa TAKAHASHI, Takumi HASEGAWA, Yuichi EGI, Katsuhiko SAKAMOTO

    2021年10月28日, European Journal of Biological Research, 11 (4), 519 - 523

    [査読有り]

  • Tomohide UNO, Yusuke OZAKIYA, Mako SASAO, Katsuhiko SAKAMOTO, Yasuo YAMAUCHI, Yuichi UNO, Kengo KANAMARU, Akira MIZOGUCHI

    Rab proteins are small GTP-binding proteins and are the largest family in the Ras GTPase superfamily and mediate vesicular transport in cells. Diverse insulin-like peptides, such as bombyxin, are synthesized in the brain and secreted into the haemolymph by the corpus allatum (CA). In the brain of Bombyx mori, Rabs are expressed in a specific area; however, which Rabs actually link the secretion of bombyxin remains unknown. A double-staining analysis of nine Rabs ( Rab1, 3, 6, 7, 14, 21, 26, 39 and X4) and bombyxin indicated that Rab3-, Rab7-, Rab39-and RabX4-immunohistochemical reactivity (ir) areas overlapped with bombyxin-ir in the brain and CA in B. mori, while Rab6-, Rab14-and Rab21-irs partially overlapped in the CA. Rab1-ir occurred in the other immunopositive areas in CA. Rab26-ir did not occur in the brain. Rab39-ir occurred in UNC104, Rab39- effector,-immunopositive neurons in the brain and CA. Thus, Rab3, 7, 39 and X4 may regulate the exocytosis of bombyxin.

    Biology Centre, AS CR, 2021年10月07日, European Journal of Entomology, 118, 307 - 314, 英語

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    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Sayaka Higo-Yamamoto, Yuichi Egi, Koyomi Miyazaki, Katsutaka Oishi

    Elsevier BV, 2020年08月, Biochemical and Biophysical Research Communications, 529 (2), 175 - 179

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    研究論文(学術雑誌)

  • Hiroki Okauchi, Sayaka Higo-Yamamoto, Takumi Sowa, Hideaki Oike, Saori Yamamoto, Naoyuki Wada, Katsuhiko Sakamoto, Katsutaka Oishi

    Elsevier BV, 2020年03月, Biochemical and Biophysical Research Communications, 524 (1), 129 - 134

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    研究論文(学術雑誌)

  • Functional characterization of insect-specific RabX6 of Bombyx mori

    Tomohide UNO, Yusuke OZAKIYA, Masayuki FURUTANI, Katsuhiko SAKAMOTO, Yuichi UNO, Kengo KANAMARU, Akira MIZOGUCHI

    2019年01月, Histochemistry and Cell Biology, 151, 187 - 198, 英語

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    研究論文(学術雑誌)

  • Ginga SHIMAKAWA, Kentaro IFUKU, Yuji SUZUKI, Amane MAKINO, Kimitsune ISHIZAKI, Hiroshi FUKAYAMA, Ryutaro MORITA, Katsuhiko SAKAMOTO, Akiko NISHI, Chikahiro MIYAKE

    Sugar metabolism pathways such as photosynthesis produce dicarbonyls, e.g. methylglyoxal ( MG), which can cause cellular damage. The glyoxalase ( GLX) system comprises two enzymes GLX1 and GLX2, and detoxifies MG; however, this system is poorly understood in the chloroplast, compared with the cytosol. In the present study, we determined GLX1 and GLX2 activities in spinach chloroplasts, which constituted 40% and 10%, respectively, of the total leaf glyoxalase activity. In Arabidopsis thaliana, five GFP-fusion GLXs were present in the chloroplasts. Under high CO2 concentrations, where increased photosynthesis promotes the MG production, GLX1 and GLX2 activities in A. thaliana increased and the expression of AtGLX1-2 and AtGLX2-5 was enhanced. On the basis of these findings and the phylogeny of GLX in oxygenic phototrophs, we propose that the GLX system scavenges MG produced in chloroplasts during photosynthesis.

    Japan Society for Bioscience, Biotechnology, and Agrochemistry, 2018年12月, Bioscience, Biotechnology and Biochemistry, 82 (12), 2072 - 2083, 英語

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    研究論文(学術雑誌)

  • Effects of mild and low temperature incubation on heat tolerance in Bombyx mori embryos.

    Daisuke MATSUOKA, Katsuhiko SAKAMOTO

    2018年07月, American Journal of Entomology, 2 (2), 6 - 9, 英語

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    研究論文(学術雑誌)

  • Tomohide Uno, Masayuki Furutani, Katsuhiko Sakamoto, Yuichi Uno, Kengo Kanamaru, Akira Mizoguchi, Susumu Hiragaki, Makio Takeda

    Rab proteins are small monomeric GTPases/GTP-binding proteins, which form the largest branch of the Ras superfamily. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they function as regulators of distinct steps in membrane trafficking. RabX4 is an insect-specific Rab protein that has no close homolog in vertebrates. There is little information about insect-specific Rab proteins. RabX4 was expressed in Escherichia coli and subsequently purified. Antibodies against Bombyx mori RabX4 were produced in rabbits for western immunoblotting and immunohistochemistry. Western blotting of neural tissues revealed a single band, at approximately 26kD. RabX4-like immunohistochemical reactivity was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum in the brain. Further immunohistochemical analysis revealed that RabX4 colocalized with Rab6 and bombyxin in the corpus allatum, a neuronal organ that secretes neuropeptides synthesized in the brain into the hemolymph. RabX4 expression in the frontal ganglion, part of the insect stomatogastric nervous system that is found in most insect orders, was restricted to two neurons on the outer region and did not colocalize with allatotropin or Rab6. Furthermore, RNA interference of RabX4 decreased bombyxin expression levels in the brain. These findings suggest that RabX4 is involved in the neurosecretion of a secretory organ in Bombyx mori.

    WILEY, 2017年09月, ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY, 96 (1), 英語

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    研究論文(学術雑誌)

  • Shion Akitomo, Yuichi Egi, Yuki Nakamura, Yoshitaka Suetsugu, Katsutaka Oishi, Katsuhiko Sakamoto

    The bivoltine silkworm Bombyx mori (Lepidoptera: Bombycidae) exhibits a maternally controlled embryonic diapause. Maternal silkworms decide whether to lay diapause or nondiapause eggs depending on environmental factors such as the temperature and photoperiod during the egg and larval stages, and then induce diapause eggs during the pupal stage. However, little is known about the molecular mechanism that conveys the outcome of whether to produce diapause or nondiapause eggs from the egg or larval stages to the pupal stage. This study used microarray analysis to investigate differentially expressed genes in the larval brains of diapause- and nondiapause-egg producers, to which bivoltine silkworms were destined by thermal or photic stimulation during the egg stage. The cytochrome P450 18a1 and Kruppel homolog 1 genes were upregulated in producers of diapause eggs compared with those of nondiapause eggs under both experimental conditions. Cytochrome P450 18a1 encodes a key enzyme for steroid hormone inactivation and Kruppel homolog 1 is an early juvenile hormone-inducible gene that mediates the repression of metamorphosis. The upregulation of these genes during the larval stage might be involved in the signaling pathway that transmits information about the diapause program from the egg stage to the pupal stage in the silkworm.

    WILEY, 2017年04月, INSECT SCIENCE, 24 (2), 187 - 193, 英語

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    研究論文(学術雑誌)

  • Tomohide Uno, Masayuki Furutani, Chihiro Watanabe, Katsuhiko Sakamoto, Yuichi Uno, Kengo Kanamaru, Hiroshi Yamagata, Akira Mizoguchi, Makio Takeda

    In eukaryotic cells, Rab guanosine triphosphate-ases serve as key regulators of membrane-trafficking events, such as exocytosis and endocytosis. Rab3, Rab6, and Rab27 control the regulatory secretory pathway of neuropeptides and neurotransmitters. The cDNAs of Rab3, Rab6, and Rab27 from B. mori were inserted into a plasmid, transformed into Escherichia coli, and then subsequently purified. We then produced antibodies against Rab3, Rab6, and Rab27 of Bombyx mori in rabbits and rats for use in western immunoblotting and immunohistochemistry. Western immunoblotting of brain tissue revealed a single band at approximately 26 kDa. Immunohistochemistry results revealed that Rab3, Rab6, and Rab27 expression was restricted to neurons in the pars intercerebralis and dorsolateral protocerebrum of the brain. Rab3 and Rab6 co-localized with bombyxin, an insect neuropeptide. However, there was no Rab that co-localized with prothoracicotropic hormone. The corpus allatum secretes neuropeptides synthesized in the brain into the hemolymph. Results showed that Rab3 and Rab6 co-localized with bombyxin in the corpus allatum. These findings suggest that Rab3 and Rab6 are involved in neurosecretion in B. mori. This study is the first to report a possible relationship between Rab and neurosecretion in the insect corpus allatum.

    SPRINGER, 2016年07月, HISTOCHEMISTRY AND CELL BIOLOGY, 146 (1), 59 - 69, 英語

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    研究論文(学術雑誌)

  • Does DNA methylation play a role in photoperiodic diapause of moths?

    Yuichi EGI, Hiroki TSUBOUCHI, Katsuhiko SAKAMOTO

    The present study pharmacologically investigated the involvement of DNA methylation in photoperiodic diapause of the domestic silkworm Bombyx mori (Lepidoptera: Bombycidae) and the Chinese giant silkmoth Antheraea pernyi (Lepidoptera: Saturniidae). The DNA methyltransferase inhibitor 5-azacytidine was dietarily given to larvae of B. mori under short days or long days. However,

    AkiNik Publications, 2016年07月, Journal of Entomology and Zoology Studies, 4 (4), 458 - 460, 英語

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    研究論文(学術雑誌)

  • Daisuke Takagi, Kentaro Ifuku, Ken-ichi Ikeda, Kanako Ikeda Inoue, Pyoyun Park, Masahiro Tamoi, Hironori Inoue, Katsuhiko Sakamoto, Ryota Saito, Chikahiro Miyake

    Lipid-derived reactive carbonyl species (RCS) possess electrophilic moieties and cause oxidative stress by reacting with cellular components. Arabidopsis (Arabidopsis thaliana) has a chloroplast-localized alkenal/one oxidoreductase (AtAOR) for the detoxification of lipid-derived RCS, especially alpha,beta-unsaturated carbonyls. In this study, we aimed to evaluate the physiological importance of AtAOR and analyzed AtAOR (aor) mutants, including a transfer DNA knockout, aor (T-DNA), and RNA interference knockdown, aor (RNAi), lines. We found that both aor mutants showed smaller plant sizes than wild-type plants when they were grown under day/night cycle conditions. To elucidate the cause of the aor mutant phenotype, we analyzed the photosynthetic rate and the respiration rate by gas-exchange analysis. Subsequently, we found that both wildtype and aor (RNAi) plants showed similar CO2 assimilation rates; however, the respiration rate was lower in aor (RNAi) than in wild-type plants. Furthermore, we revealed that phosphoenolpyruvate carboxylase activity decreased and starch degradation during the night was suppressed in aor (RNAi). In contrast, the phenotype of aor (RNAi) was rescued when aor (RNAi) plants were grown under constant light conditions. These results indicate that the smaller plant sizes observed in aor mutants grown under day/night cycle conditions were attributable to the decrease in carbon utilization during the night. Here, we propose that the detoxification of lipid-derived RCS by AtAOR in chloroplasts contributes to the protection of dark respiration and supports plant growth during the night.

    AMER SOC PLANT BIOLOGISTS, 2016年04月, PLANT PHYSIOLOGY, 170 (4), 2024 - 2039, 英語

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    研究論文(学術雑誌)

  • Yuichi Egi, Katsuhiko Sakamoto

    This study investigated daily changes in susceptibility to insecticides in the silkworm Bombyx mori (Lepidoptera: Bombycidae). The daily rhythm of permethrin susceptibility in fifth instar larvae of the p63-silkworm strain was significant, with the lowest mortality rate during the late photophase under a 12-h light-12-h dark cycle. The rhythms were similar whether permethrin was intraperitoneally injected into hemolymph or topically applied to the dorsal abdomen. Drug intake through the cuticle probably did not significantly contribute to the organization of this susceptibility rhythm. We also found that the daily susceptibility profiles depended on insecticide type and silkworm strain. Temporal susceptibility variations might be attributable to the drug metabolic system. To our knowledge, this is the first description of an insecticide susceptibility rhythm in the larval stage of lepidopteran insects. Specifically timed delivery of insecticides might enable more efficient control of pest caterpillars that cause serious crop damage.

    TAYLOR & FRANCIS LTD, 2016年03月, BIOLOGICAL RHYTHM RESEARCH, 47 (2), 247 - 252, 英語

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    研究論文(学術雑誌)

  • Takuma Nishimura, Tomohiro Fujii, Katsuhiko Sakamoto, Kaoru Maeto

    The braconid parasitoid wasp that attacks exposed lepidopteran larvae, Meteorus pulchricornis (Wesmael), is a common natural enemy of pest caterpillars and may serve as a biological control agent. Recently spreading nighttime lighting for the control of noctuid moths may affect the behavior of the parasitoid if it is nocturnal, but little is known about its daily activity patterns. This study investigated the locomotor activity of M. pulchricornis under various light conditions. Over a daily 16-h light:8-h dim light cycle (16L8Dim), the wasps were inactive during most of the photophase (16L), gradually becoming active late in the photophase, with activity levels peaking just after the switch to the scotophase (8Dim). Subsequently, during the scotophase, activity decreased to a moderate level and continued at that level until the switch to the photophase. In addition, after transfer from daily light/dim light cycles (16L8Dim), daily fluctuations in activity persisted for at least 1 day under continuous light or dim light conditions. This is the first report describing the nocturnal activity rhythm of parasitoid wasps and the suppression of their activity under strong light conditions.

    SPRINGER JAPAN KK, 2015年11月, APPLIED ENTOMOLOGY AND ZOOLOGY, 50 (4), 525 - 531, 英語

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    研究論文(学術雑誌)

  • Qiushi Wang, Ikumi Hanatani, Makio Takeda, Katsutaka Oishi, Katsuhiko Sakamoto

    The present study investigated the pharmacological properties of dopamine receptors that functioned in the termination of pupal diapause in the Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae). Dopamine receptors are classified according to their structure and function into two subfamilies as D1- and D2-like receptors. D1-like receptors activate, whereas D2-like receptors inhibit, adenylate cyclase. We examined the effects of agonists and antagonists selective for D1- and D2-like receptors on the diapause state. As A.pernyi is a long-day species, pupal diapause is maintained during short days and can be terminated by exposure to a long-day photoperiod. The D2-like receptor-selective agonist quinpirole delayed the timing of adult emergence under long days, and the D2-receptor-selective antagonist sulpiride terminated pupal diapause even under a short-day photoperiod. The D1-like receptor-selective agonist and antagonist, SKF-38393 and SCH-23390, respectively, caused no significant effects on diapause pupae. These results suggest that not D1- but D2-like receptors mediated diapause regulation in A.pernyi. This dopamine pathway appeared to block the termination of pupal diapause. Furthermore, the actions of the cAMP analog 8-CPT-cAMP and dopamine receptor antagonists upon diapause pupae were similar, which supports the notion that D2-like receptors involved in diapause of this insect prevent adenylate cyclase from producing cAMP like vertebrate D2-like receptors. Taken together, our findings suggest that dopamine blocked diapause termination through D2-like receptors that inhibited adenylate cyclase in A.pernyi. During short days under which diapause was maintained in pupae, the dopaminergic mechanism might be stimulated to suppress cAMP levels in cells regulating diapause.

    WILEY-BLACKWELL, 2015年04月, ENTOMOLOGICAL SCIENCE, 18 (2), 193 - 198, 英語

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    研究論文(学術雑誌)

  • Ginga Shimakawa, Keiichiro Shaku, Akiko Nishi, Ryosuke Hayashi, Hiroshi Yamamoto, Katsuhiko Sakamoto, Amane Makino, Chikahiro Miyake

    This study aims to elucidate the molecular mechanism of an alternative electron flow (AEF) functioning under suppressed (CO2-limited) photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803. Photosynthetic linear electron flow, evaluated as the quantum yield of photosystem II [Y(II)], reaches a maximum shortly after the onset of actinic illumination. Thereafter, Y(II) transiently decreases concomitantly with a decrease in the photosynthetic oxygen evolution rate and then recovers to a rate that is close to the initial maximum. These results show that CO2 limitation suppresses photosynthesis and induces AEF. In contrast to the wild type, Synechocystis sp. PCC 6803 mutants deficient in the genes encoding FLAVODIIRON2 (FLV2) and FLV4 proteins show no recovery of Y(II) after prolonged illumination. However, Synechocystis sp. PCC 6803 mutants deficient in genes encoding proteins functioning in photorespiration show AEF activity similar to the wild type. In contrast to Synechocystis sp. PCC 6803, the cyanobacterium Synechococcus elongatus PCC 7942 has no FLV proteins with high homology to FLV2 and FLV4 in Synechocystis sp. PCC 6803. This lack of FLV2/4 may explain why AEF is not induced under CO2-limited photosynthesis in S. elongatus PCC 7942. As the glutathione S-transferase fusion protein overexpressed in Escherichia coli exhibits NADH-dependent oxygen reduction to water, we suggest that FLV2 and FLV4 mediate oxygen-dependent AEF in Synechocystis sp. PCC 6803 when electron acceptors such as CO2 are not available.

    AMER SOC PLANT BIOLOGISTS, 2015年02月, PLANT PHYSIOLOGY, 167 (2), 472 - U732, 英語

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    研究論文(学術雑誌)

  • Qiushi Wang, Yuichi Egi, Makio Takeda, Katsutaka Oishi, Katsuhiko Sakamoto

    The present study investigated the functional involvement of melatonin and dopamine in photoperiodism to terminate pupal diapause in the Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae). Diapause in this long-day (short-night) species is maintained during long nights and can be terminated by exposure to a short-night photoperiod. We observed the effects of melatonin and dopamine and their receptor antagonists on diapause pupae. Melatonin and flupentixol, a dopamine receptor antagonist, terminated pupal diapause even under long-night photoperiods. Dopamine and luzindole, a melatonin receptor antagonist, retarded adult emergence during short nights, whereas melatonin advanced the timing of adult emergence under the short-night photoperiod in a manner dependent on the number of injections. The results of the day-length extension experiment indicated that a change in the photoperiod was immediately detected as mRNA expression of the rate-limiting enzyme of melatonin production. These findings suggest that the melatonin pathway transmits information on the photoperiod to terminate the pupal diapause of A.pernyi. The melatonin pathway also inhibited the dopamine production system, and the dopamine pathway inhibited the melatonin production system. We propose an insect model of the photoperiodic counter driven by mutual inhibition between the melatonin and dopamine pathways.

    WILEY-BLACKWELL, 2015年01月, ENTOMOLOGICAL SCIENCE, 18 (1), 74 - 84, 英語

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    研究論文(学術雑誌)

  • Yuichi Egi, Shion Akitomo, Tsuguru Fujii, Yutaka Banno, Katsuhiko Sakamoto

    In the silkworm, Bombyx mori (Lepidoptera: Bombycidae), embryonic diapause is under maternal control and the decision between diapause and direct development in bivoltine strains depends on environmental factors such as temperature and photoperiod experienced by the preceding generation. We reared ten bivoltine silkworm strains (c10, g32, k06, n25, p21, p22, p24, p44, p50 and p63) under various thermal and light conditions and examined the incidence of embryonic diapause in the next generation to identify strains in which the incidence of diapause can be controlled within the range of 0 to 100% by adjusting a single ambient parameter. Some strains were clearly destined towards either diapause or direct development. The diapause incidence in the c10, p22 and p50 strains was controlled by temperature during the egg stage (0% at 18 degrees C and 100% at 25 degrees C), that in the p50 strain was also determined to be dependent on illumination during the egg stage (0% under continuous darkness and 100% under continuous illumination), and photoperiod during the larval stage regulated diapause in p44 and p50 (0% and 100% under long-day and short-day photoperiod, respectively), when all other external parameters remained constant under each experimental condition. These diapause-controllable silkworm strains might serve as model systems for studies of insect diapause, especially for the differential screening of related factors.

    WILEY-BLACKWELL, 2014年10月, ENTOMOLOGICAL SCIENCE, 17 (4), 396 - 399, 英語

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    研究論文(学術雑誌)

  • Tomohide Uno, Yuri Isoyama, Kazuki Sakamoto, Yuichi Uno, Katsuhiko Sakamoto, Kengo Kanamaru, Hiroshi Yamagata, Michihiro Takagi, Akira Mizoguchi, Makio Takeda

    Rab guanosine triphosphatases in eukaryotic cells are key regulators of membrane-trafficking events, such as exocytosis and endocytosis. Rab7 regulates traffic from early to late endosomes and from late endosomes to vacuoles/lysosomes. The Rab7-interacting lysosomal protein (RILP) was extracted from the silkworm, Bombyx mori (B. mori), and expressed in Escherichia coli (E. coli), followed by its purification. The glutathione sulfotransferase pull-down assay revealed that Rab7 of B. mori interacted with RILP of B. mori. We then produced antibodies against RILP of B. mori in rabbits for their use in Western immunoblotting and immunohistochemistry. Western immunoblotting of brain tissue for RILP revealed a single band, at approximately 50 kD. RILP-like immunohistochemical reactivity (RILP-ir) was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum. Furthermore, RILP-ir was colocalized with the eclosion hormone-ir and bombyxin-ir. However, RILP-ir was not colocalized with prothoracicotropic hormone-ir. These results were similar to those of Rab7 from our previous study. These findings suggest that RILP and Rab7 are involved in the neurosecretion in a restricted subtype of neurons in B. mori. Thus, our study is the first to report of a possible relationship between an insect Rab effector and neurosecretion.

    SPRINGER, 2014年03月, HISTOCHEMISTRY AND CELL BIOLOGY, 141 (3), 311 - 320, 英語

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    研究論文(学術雑誌)

  • Moon Soo Park, Yuichi Egi, Makio Takeda, Katsuhiko Sakamoto

    Insects have both a circadian oscillatory system in peripheral tissues and a master clock in the central nervous system. However, the distribution of oscillator cells in the digestive system that is indispensable for nutrient intake has not been described in detail. This study immunohistochemically investigates cellular localization of the clock protein PERIOD in the larval midgut of the silkworm Bombyx mori (Lepidoptera: Bombycidae). PERIOD-like immunoreactivity was not uniformly distributed and was located exclusively in goblet cells of the midgut epithelium. The primary role of goblet cells is the active transport of potassium from hemolymph into the gut lumen. However, these cells might function as a peripheral clock that regulates the daily rhythms of physiological activities in the midgut of silkworm larvae.

    TAYLOR & FRANCIS LTD, 2014年, BIOLOGICAL RHYTHM RESEARCH, 45 (3), 369 - 374, 英語

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    研究論文(学術雑誌)

  • Ryota Saito, Ginga Shimakawa, Akiko Nishi, Tatsuya Iwamoto, Katsuhiko Sakamoto, Hiroshi Yamamoto, Katsumi Amako, Amane Makino, Chikahiro Miyake

    In Arabidopsis thaliana, the aldo-keto reductase (AKR) family includes four enzymes (The AKR4C subfamily: AKR4C8, AKR4C9, AKR4C10, and AKR4C11). AKR4C8 and AKR4C9 might detoxify sugar-derived reactive carbonyls (RCs). We analyzed AKR4C10 and AKR4C11, and compared the enzymatic functions of the four enzymes. Modeling of protein structures based on the known structure of AKR4C9 found an (alpha/beta)(8)-barrel motif in all four enzymes. Loop structures (A, B, and C) which determine substrate specificity, differed among the four. Both AKR4C10 and AKR4C11 reduced methylglyoxal. AKR4C10 reduced triose phosphates, dihydroxyacetone phosphate (DHAP), and glyceraldehydes 3-phosphate (GAP), the most efficiently of all the AKR4Cs. Acrolein, a lipid-derived RC, inactivated the four enzymes to different degrees. Expression of the AKR4C genes was induced under high-[CO2] and high light, when photosynthesis was enhanced and photosynthates accumulated in the cells. These results suggest that the AKR4C subfamily contributes to the detoxification of sugar-derived RCs in plants.

    TAYLOR & FRANCIS LTD, 2013年10月, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 77 (10), 2038 - 2045, 英語

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    研究論文(学術雑誌)

  • Ginga Shimakawa, Mayumi Suzuki, Eriko Yamamoto, Akiko Nishi, Ryota Saito, Katsuhiko Sakamoto, Hiroshi Yamamoto, Amane Makino, Chikahiro Miyake

    To elucidate the scavenging systems of sugar- and lipid-derived reactive carbonyls (RCs) in the cyanobacterium Synechocystis sp. PCC 6803 (S. 6803), we selected proteins from S. 6803 based on amino-acid (AA) sequence similarities with proteins from Arabidopsis thaliana, and characterized the properties of the GST-fusion proteins expressed. Slr0942 catalyzed the aldo-keto reductase (AKR) reaction scavenging mainly sugar-derived RCs, methylglyoxal (MG). Slr1192 is the medium-chain dehydrogenase/redutase (MDR). It catalyzed the AKR reaction scavenging several lipid-derived RCs, acrolein, propionaldehyde, and crotonaldehyde. Slr0315 is a short-chain dehydrogenase/redutase (SDR), and it catalyzed only the reduction of MG in the AKR reaction. Slr0381 catalyzed the conversion of hemithioacetal to S-lactoylglutahione (SLG) in the glyoxalase (GLX) 1 reaction. Sll1019 catalyzed the conversion of SLG to glutathione and lactate in the GLX2 reaction. GLX1 and GLX2 compose the glyoxalase system, which scavenges MG. These enzymes contribute to scavenging sugar- and lipid-derived RCs as scavenging systems.

    Japan Society for Bioscience, Biotechnology, and Agrochemistry, 2013年, Bioscience, Biotechnology and Biochemistry, 77 (12), 2441 - 2448, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Hiroyuki Nobata, Katsutaka Oishi, Makio Takeda, Katsuhiko Sakamoto

    To investigate the photoreception that controls daily oscillations at the periphery in insects, we decapitated larvae of the silkworm Bombyx mori (Lepidoptera: Bombycidae) by ligature, and observed rhythms in their peripheral tissues under several light conditions. We measured the mRNA expression of period (per) and timeless (tim), which are homologues of Drosophila clock genes that function in the core oscillator of the circadian clock system. The expression of both per and tim significantly changed in the midgut, Malpighian tubules and silk glands of decapitated larvae exposed to photophase and scotophase that were reversed from the original daily lightdark cycle under which the larvae were housed. Under constant darkness, the daily expression of tim mRNA persisted for at least one cycle in the midgut and silk gland. In addition, an appropriate light stimulus under constant darkness induced a significant phase shift in the endogenous timing system (probably a circadian clock) that determined peak levels of tim mRNA expression in the midgut and silk glands of decapitated larvae. Since light regulated the gene expression rhythm in peripheral tissues of decapitated silkworm larvae, neither the brain nor eyes were essential for photoreception to control daily oscillations in these tissues. Thus, peripheral tissues in insects might directly use light even at the larval stage.

    WILEY-BLACKWELL, 2012年10月, ENTOMOLOGICAL SCIENCE, 15 (4), 392 - 399, 英語

    [査読有り]

    研究論文(学術雑誌)

  • FGF21 is dispensable for hypothermia induced by fasting in mice

    Katsutaka Oishi, Katsuhiko Sakamoto, Morichika Konishi, Yusuke Murata, Nobuyuki Itoh, Hiroyoshi Sei

    BACKGROUND: Fibroblast growth factor 21 (FGF21) is a key metabolic regulator that is induced by peroxisome proliferator-activated receptor alpha (PPAR alpha) activation in response to fasting. We recently reported that bezafibrate, a panagonist of PPARs, decreases body temperature late at night through hypothalamic neuropeptide Y (NPY) activation and others have shown that mice overexpressing FGF21 are prone to torpor. OBJECTIVES: We examined whether FGF21 is essential for fasting-induced hypothermia using FGF21 knockout (KO) mice. RESULTS: Acute fasting decreased body temperature late at night accompanied by the induction of hepatic FGF21 and hypothalamic NPY expression in wild-type mice. A deficiency of FGF21 affected neither fasting-induced hypothermia nor hypothalamic NPY induction. Fasting enhanced locomotor activity in both genotypes. On the other hand, a deficiency of FGF21 significantly attenuated chronic hypothermia and hypoactivity induced by a ketogenic diet (KD). CONCLUSIONS: Our findings suggest that FGF21 is not essential for the hypothermia that is associated with the early stages of fasting, although it might be involved in the adaptive response of body temperature to chronic starvation.

    MAGHIRA & MAAS PUBLICATIONS, 2010年, NEUROENDOCRINOLOGY LETTERS, 31 (2), 198 - 202, 英語

    [査読有り]

    研究論文(学術雑誌)

  • R. Morioka, M. Arita, K. Sakamoto, S. Kawaguchi, H. Tei, K. Horimoto

    Many genes related to the circadian rhythm, especially those involved in phase shifts induced by different environmental stimuli, still remain enigmatic. In this study, the authors monitored the expression of rat genes measured with multiple phase-resetting stimuli, and developed a technique to extract the candidate genes for the changes in circadian rhythm by the stimuli, from microarray data. First, the spectra for the time series of gene expression were estimated by fast Fourier transform, and then two fitting methods, the random period fitting method and the conditional curve fitting method, using the estimated periods as the initial values, were applied to the control and the stimulated expression data to estimate the periods and the phases. Finally, by comparing the two sets of periods and phases, the period change and the phase shift by stimuli were estimated to extract the candidate genes related to the master clock, by mapping the period change and the phase shift on a two-dimensional space, a period-phase map (PPM). As an indirect validation of the genes selected by our method, the significant enrichment of extracted gene clusters on the PPM was further evaluated, in terms of biological function. As a result, the gene clusters related to photoreceptors and neural regulation emerged on the PPM, thus implying the relationships in the stimulus response of the master clock that resides in the brain at the intersection of the optic nerves. Thus, the present approach is a feasible means to explore the oscillatory genes related to stimulus responses.

    INST ENGINEERING TECHNOLOGY-IET, 2009年11月, IET SYSTEMS BIOLOGY, 3 (6), 487 - 495, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Gianluca Tosini, Manami Kasamatsu, Katsuhiko Sakamoto

    Elsevier BV, 2007年07月, Brain Research, 1159, 134 - 140

    [査読有り]

    研究論文(学術雑誌)

  • Intraocular injection of kainic acid does not abolish the circadian rhythm of arylalkylamine N-acetyltransferase mRNA in rat photoreceptors.

    Katsuhiko Sakamoto, Cuimei Liu, Manami Kasamatsu, P Michael Iuvone, Gianluca Tosini

    2006年02月23日, Molecular Vision, 12, 117 - 124

    [査読有り]

  • Katsuhiko Sakamoto, Cuimei Liu, Manami Kasamatsu, Nikita V. Pozdeyev, P. Michael Iuvone, Gianluca Tosini

    Wiley, 2005年12月, European Journal of Neuroscience, 22 (12), 3129 - 3136

    [査読有り]

    研究論文(学術雑誌)

  • Jadwiga Bembenek, Katsuhiko Sakamoto, Makio Takeda

    Wiley, 2005年08月, Archives of Insect Biochemistry and Physiology, 59 (4), 219 - 229

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Cuimei Liu, Gianluca Tosini

    Recent studies have demonstrated that melanopsin is a key photopigment in the mammalian circadian system. This novel opsin is exclusively expressed in retinal ganglion cells that are intrinsically sensitive to light, perhaps responding via a melanopsin-based signaling pathway. Previous investigations using transgenic mice have also demonstrated that ablation of the classical photoreceptors and of melanopsin prevents entrainment of several circadian rhythms, thus demonstrating that these photoreceptors are necessary and sufficient for circadian photoreception. In this study, we investigated the effect of photoreceptor degeneration onmelanopsinmRNA regulation in RCS/N-rdyrats (Royal College of Surgeons rats with a defect in the retinal dystrophy gene). We used animals at postnatal day 21 (P21), P33, P45, and P60. At P60 degeneration of the retina in RCS/N-rdyhas advanced to the point where the majority of the photoreceptors have degenerated. Our data indicate thatmelanopsinmRNA levels were rhythmic in light/dark cycle and in constant darkness in congenic controls (RCS/N-rdy+) and in RCS/N-rdyat P21 (i.e., before the degeneration of the photoreceptors). On the other hand, in RCS/N-rdyat P60,melanopsinmRNA levels were greatly reduced (<90%) and not rhythmic. Photoreceptor degeneration did not affect the expression ofpituitary adenylate cyclase-activating polypeptidemRNA (a marker for melanopsin-containing ganglion cells). Our results suggest that classical photoreceptors (rods and cones) regulate the expression ofmelanopsinmRNA in the rat. Because RCS/N-rdyrats are a model for studies on retinitis pigmentosa in human, our data may provide an important insight on melanopsin function in patients affected by retinitis pigmentosa.

    Society for Neuroscience, 2004年10月27日, The Journal of Neuroscience, 24 (43), 9693 - 9697

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Cuimei Liu, Gianluca Tosini

    Wiley, 2004年08月, Journal of Neurochemistry, 90 (4), 1019 - 1024

    [査読有り]

    研究論文(学術雑誌)

  • Katsutaka Oishi, Masayuki Shiota, Katsuhiko Sakamoto, Manami Kasamatsu, Norio Ishida

    Ovid Technologies (Wolters Kluwer Health), 2004年03月, NeuroReport, 15 (4), 739 - 743

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko SAKAMOTO, Koji KADOTA, Katsutaka OISHI

    Japanese Association for Laboratory Animal Science, 2004年, Experimental Animals, 53 (5), 471 - 474

    [査読有り]

    研究論文(学術雑誌)

  • Katsutaka Oishi, Katsuhiko Sakamoto, Norio Ishida

    Elsevier BV, 2003年11月, Neuroscience Letters, 351 (1), 21 - 24

    [査読有り]

    研究論文(学術雑誌)

  • Paraskevi Moutsaki, David Whitmore, James Bellingham, Katsuhiko Sakamoto, Zoë K. David-Gray, Russell G. Foster

    Elsevier BV, 2003年04月, Molecular Brain Research, 112 (1-2), 135 - 145

    [査読有り]

    研究論文(学術雑誌)

  • Markova EP, Ueda H, Sakamoto K, Oishi K, Shimada T, Takeda M

    Cycle (Bmal1) is one of the circadian clock genes and the key regulator of the circadian system in many organisms, encoding a bHLH-PAS transcription factor. In the present study, we cloned cycle homolog (BmCyc) in Bombyx mori. We performed polymerase chain reaction with degenerated primers deduced from the conserved amino acid sequences of mammalian BMAL1 and Drosophila CYCLE. Then the partial clone obtained was used as a probe for screening a cDNA library constructed from pupal brains of B. mori. BmCyc is 5703 nucleotides long and encodes 700 amino acid residues. The BmCYC has bHLH, PAS A and PAS B domains, and the sequence identities for these domains are 85, 60 and 50%, to Drosophila CYCLE (dCYC) and 69, 58 and 50%, to human BMAL1 (hBMAL1), respectively. The deduced amino acid sequence of BmCYC is 37% identical to that of dCYC and 28% to hBMAL1. Northern blot analysis demonstrates that BmCyc gene was expressed in all the tissues tested, which were head, fat body, silk glands, and midgut. Also no significant day, night time-specific difference in expression of BmCyc gene in the head was detected. (C) 2002 Elsevier Science Inc. All rights reserved.

    3, 2003年03月, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology, 134 (3), 535 - 542, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Rihito Asai, Atsushi Okada, Isamu Shimizu

    Informa UK Limited, 2003年02月, Biological Rhythm Research, 34 (1), 61 - 71

    [査読有り]

    研究論文(学術雑誌)

  • Katsutaka Oishi, Hiromi Fukui, Katsuhiko Sakamoto, Koyomi Miyazaki, Hisato Kobayashi, Norio Ishida

    Elsevier BV, 2002年12月, Molecular Brain Research, 109 (1-2), 11 - 17

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Katsutaka Oishi, Takahiro Nagase, Koyomi Miyazaki, Norio Ishida

    Ovid Technologies (Wolters Kluwer Health), 2002年07月, Neuroreport, 13 (10), 1239 - 1242

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto

    Informa UK Limited, 2002年02月, Biological Rhythm Research, 33 (1), 75 - 81

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Katsutaka Oishi, Norio Ishida

    Elsevier BV, 2002年01月, Neuroscience Letters, 317 (1), 53 - 55

    [査読有り]

    研究論文(学術雑誌)

  • Photoperiodic and circadian photoreception in the silkworm, Bombyx mori.

    Shimizu, I., Sakamoto, K. and Iwasa

    2002年, Journal of Photoscience, 9, 17 - 20

    [査読有り]

  • Tetsuya Okada, Takaomi Sakai, Takehide Murata, Koichiro Kako, Katsuhiko Sakamoto, Michiko Ohtomi, Tatsuo Katsura, Norio Ishida

    Elsevier BV, 2001年05月, Biochemical and Biophysical Research Communications, 283 (3), 577 - 582

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Katsutaka Oishi, Maki Shiraishi, Satoshi Hamano, Hitoki Otsuka, Yoshiaki Miyake, Norio Ishida

    Ovid Technologies (Wolters Kluwer Health), 2000年12月, NeuroReport, 11 (18), 3995 - 3997

    [査読有り]

    研究論文(学術雑誌)

  • Katsutaka Oishi, Ichiro Murai, Katsuhiko Sakamoto, Hitoki Otsuka, Yoshiaki Miyake, Takahiro Nagase, Norio Ishida

    Elsevier BV, 2000年12月, Brain Research, 885 (2), 298 - 302

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Norio Ishida

    Wiley, 2000年11月, European Journal of Neuroscience, 12 (11), 4003 - 4006

    [査読有り]

    研究論文(学術雑誌)

  • Temporal expression pattern of circadian clock genes in the maternal and fetal heart and placenta of rats.

    Otsuka, H, Sakamoto, K, Oishi, K, Miyake, Y, Sato, K, Ishida, N

    2000年, Acta Obstetrica et Gynaecologica Japonica, 52, 11 - 18

    [査読有り]

  • K Sakamoto, K Oishi, T Okada, Y Onuma, K Yokoyama, K Sugimoto, N Ishida

    The primary structure of the cone-rod homeobox protein (CRX), a member of the OTX-like homeobox protein family, in the rat was deduced from the cDNA nucleotide sequence. The deduced protein consisted of 299 amino acid residues with motifs conserved in mammalian CRXs, and was 98% identical to mouse CRX. Northern blot analysis showed that Crx mRNA levels in the rat retina were constant under a daily light-dark cycle. These findings suggest that the expression mechanism of rat Crx in the retina was different from that in the pineal, where Crx mRNA exhibits a daily expression rhythm. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

    ELSEVIER SCI IRELAND LTD, 1999年02月, NEUROSCIENCE LETTERS, 261 (1-2), 101 - 104, 英語

    [査読有り]

    研究論文(学術雑誌)

  • K Oishi, K Sakamoto, T Okada, T Nagase, N Ishida

    BMAL1 is a putative transcription factor which is involved in circadian rhythm generation in Drosophila. Northern blot analysis was performed to investigate the expression of rat BMAL1 mRNA in the suprachiasmatic nucleus (SCN) and peripheral tissues. In the SCN, circadian expression of BMAL1 mRNA which reaches its peak level at the time of dark-light transition was observed, and the expression pattern was antiphase to those of two period (per) homologues, rPer1 and rPer2. However, no circadian oscillation for rat Clock mRNA was detected. The circadian expression of BMAL1 mRNA was also observed in peripheral tissues such as brain (excluding the SCN), eye, heart, kidney, and lung. The amplitudes of BMAL1 and rPer2 mRNA expression levels were correlated between the different tissues, suggesting that the circadian expression of BMAL1 mRNA plays an important role in generating the circadian expression of per homologue genes in mammals. (C) 1998 Academic Press.

    ACADEMIC PRESS INC, 1998年12月, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 253 (2), 199 - 203, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Katsutaka Oishi, Katsuhiko Sakamoto, Tetsuya Okada, Takahiro Nagase, Norio Ishida

    Elsevier BV, 1998年11月, Neuroscience Letters, 256 (2), 117 - 119

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Takahiro Nagase, Hiromi Fukui, Kazumasa Horikawa, Tetsuya Okada, Hitoshi Tanaka, Kazuo Sato, Yoshiaki Miyake, Osamu Ohara, Koichiro Kako, Norio Ishida

    Elsevier BV, 1998年10月, Journal of Biological Chemistry, 273 (42), 27039 - 27042

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Takaharu Seki, Sachiko Koseki, Takahito Kashiwagi, Eisuke Eguchi

    Worldwide Dragonfly Association, 1998年10月, International Journal of Odonatology, 1 (1), 15 - 31

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Norio Ishida

    Elsevier BV, 1998年07月, Neuroscience Letters, 250 (3), 181 - 184

    [査読有り]

    研究論文(学術雑誌)

  • Tomoko Niki, Toshiyuki Hamada, Michiko Ohtomi, Katsuhiko Sakamoto, Satoru Suzuki, Koichrou Kako, Yasuhiko Hosoya, Kazumasa Horikawa, Norio Ishida

    Elsevier BV, 1998年07月, Biochemical and Biophysical Research Communications, 248 (1), 115 - 120

    [査読有り]

    研究論文(学術雑誌)

  • Junko Kitamoto, Katsuhiko Sakamoto, Koichi Ozaki, Yuji Mishina, Kentaro Arikawa

    ABSTRACT This paper describes the localization of newly identified visual pigment opsins in the tiered retina of the Japanese yellow swallowtail Papilio xuthus. We first cloned three cDNAs encoding visual pigment opsins, PxRh1, PxRh2 and PxRh3, and then carried out histological in situ hybridization to localize their mRNAs in the retina. By combining the present data with our previous electrophysiological results, we concluded that both PxRh1 and PxRh2 correspond to visual pigments expressed in photoreceptor cells sensitive in the green wavelength region (green receptors), whereas PxRh3 corresponds to a pigment in red receptors. The in situ hybridization studies showed that some photoreceptor cells express two opsin mRNAs. In the ventral half of the eye, all green receptors in the distal tier were labelled by both PxRh1 and PxRh2 probes. The labelling by the PxRh2 and PxRh3 probes was detected throughout the eye in the proximal tier; in 18 % of ommatidia, the probes labelled the same photoreceptor cell. These results suggest that the possible co-localization of two different visual pigments will broaden the sensitivity spectrum of the photoreceptor cells.

    The Company of Biologists, 1998年05月01日, Journal of Experimental Biology, 201 (9), 1255 - 1261

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Norio Ishida

    Elsevier BV, 1998年04月, Neuroscience Letters, 245 (2), 113 - 116

    [査読有り]

    研究論文(学術雑誌)

  • Isamu Shimizu, Yoshinori Yamakawa, Toshifumi Minamoto, Katsuhiko Sakamoto

    Japanese Society of Applied Entomology & Zoology, 1998年, Applied Entomology and Zoology, 33 (1), 199 - 204

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Osamu Hisatomi, Fumio Tokunaga, Eisuke Eguchi

    ABSTRACT The primary structures of two opsins from the brachyuran crab Hemigrapsus sanguineus were deduced from the cDNA nucleotide sequences. Both deduced proteins were composed of 377 amino acid residues and included residues highly conserved in visual pigments of other species, and the proteins were 75 % identical to each other. The distribution of opsin transcripts in the compound eye, determined by in situ hybridization, suggested that the mRNAs of the two opsins were expressed simultaneously in all of the seven retinular cells (R1–R7) forming the main rhabdom in each ommatidium. Two different visual pigments may be present in one photoreceptor cell in this brachyuran crab. The spectral sensitivity of the compound eye was also determined by recording the electroretinogram. The compound eye was maximally sensitive at about 480 nm. These and previous findings suggest that both opsins of this brachyuran crab produce visual pigments with maximal absorption in the blue-green region of the spectrum. Evidence is presented that crustaceans possess multiple pigment systems for vision.

    The Company of Biologists, 1996年02月01日, Journal of Experimental Biology, 199 (2), 441 - 450

    [査読有り]

    研究論文(学術雑誌)

  • Isamu SHIMIZU, Masaki UEDA, Katsuhiko SAKAMOTO, Osamu HISATOMI, Fumio TOKUNAGA

    Japan Academy, 1995年, Proceedings of the Japan Academy, Series B, 71 (2), 84 - 86

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Sakamoto, Isamu Shimizu

    Silkworms ( Bombyx mori) were reared on a carotenoid-deprived artificial diet, and the carotenoid-depleted eggs of the next generation were incubated so that we could observe the effect of the depletion on the circadian rhythm of hatching. The phototactic response curves of newly hatched larvae showed that the visual photosensitivity in ocelli of larvae from the carotenoid-depleted eggs was at least 4 log units lower than that of a carotenoid-rich control group. However, the phase-shift experiment revealed that carotenoid depletion did not reduce the photosensitivity in the hatching rhythm. When the hatching rhythm was generated by exposure to a single light pulse in constant darkness, the first peak in the rhythm of the carotenoid-depleted silkworms occurred significantly earlier than that of the carotenoid-rich group, but the following second peaks of both groups were found at the same time. These results suggest that for the silkworm, carotenoid is not involved in photoreception for the hatching rhythm, but is involved in the timing of hatching.

    SAGE Publications, 1994年03月, Journal of Biological Rhythms, 9 (1), 61 - 70

    [査読有り]

    研究論文(学術雑誌)

MISC

  • K Oishi, K Sakamoto, N Ishida

    The mammalian retina has an endogenous oscillator that regulates circadian melatonin production. We examined this mechanism in the retina of rats under restricted feeding (RF) by investigating the expression rhythms of the mRNA for serotonin N-acetyltransferase (NAT), which is the rate limiting enzyme for, melatonin synthesis. Northern blots showed that RF shifted the phase of circadian mRNA expression rhythms of a circadian clock gene rat period 2 and a clock-controlled gene D-site binding protein. However, the NAT mRNA showed a bimodal rhythm pattern with one peak at midnight and the other at midday after RF, although the mRNA expression showed a single peak at midnight after ad libitum feeding. Our results suggest that NAT mRNA in the rat retina is regulated by at least two circadian oscillatory mechanisms: one is affected by feeding and the other can oscillate independent to the imposed feeding cycles. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

    ELSEVIER SCI IRELAND LTD, 2003年11月, NEUROSCIENCE LETTERS, 351 (1), 21 - 24, 英語

  • K Sakamoto, K Oishi, N Ishida

    The circadian expression of the serotonin N-acetyltransferase (NAT) gene in the rat retina is considered to be generated by an endogenous retinal clock. To investigate the developmental aspects of the clock system in the mammalian retina, we determined daily expression patterns of NAT mRNA in the retina of postnatal rats. Animals were kept under a daily light-dark cycle (LD), or transferred to constant darkness (DID) from LID, and retinal mRNA levels were examined by Northern blot analysis. NAT mRNA had begun to show a daily change in LD as early as postnatal day 2 (P2). Whereas rhythmic variations in DD were not observed until P14, at P20, a circadian oscillation had already occurred. These findings suggest that in the rat retina, even though a daily LID induced rhythmic changes in NAT mRNA levels at the early postnatal stage, it was after P14 that the retinal clock system began to regulate the circadian NAT expression. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

    ELSEVIER SCI IRELAND LTD, 2002年01月, NEUROSCIENCE LETTERS, 317 (1), 53 - 55, 英語

講演・口頭発表等

  • カイコ幼虫に対する夜間の光照射が,幼虫の生育及び次世代卵の休眠に及ぼす影響.

    岩本彩, 寺島夕稀, 江木雄一, 坂本克彦

    日本農芸化学会関西支部 第523回講演会, 2022年12月03日

  • Opsins in the ocular and extraocular photoreceptors in the marine gastropod Onchidium neurons.

    Ryota Matsuo, Sanae Kotoh, Kiyotaka Takishita, Sakamoto, K, Tatsuya Uebi, Mamiko Ozaki, Yuko Matsuo, Nishi, T

    JSCPB 2022, 2022年11月

  • チョウ目昆虫における暗期光中断を用いた休眠制御関連遺伝子の探索.

    岩本彩, 坂本克彦

    日本農芸化学会関西支部 第521回講演会, 2022年07月09日

  • マウスにおける慢性的な朝食欠食は海馬での記憶関連遺伝子の発現変動を介して認知機能を低下させる.

    大石勝隆, 岡内宏樹, 肥後(山本)明花, 宗和拓実, 大池秀明, 山本幸織, 坂本克彦

    第74回日本栄養・食糧学会大会, 2020年05月

  • アブシジン酸により誘導されるシロイヌナズナMAP3K, MAP3K17/18の下流経路の検索.

    松岡大輔, 挟間雅幸, 南森隆司, 坂本克彦

    第60回日本植物生理学会, 2019年03月13日

  • 昆虫におけるP450遺伝子の発現に及ぼす摂食の影響

    岩井酉樹, 坂本克彦

    日本農芸化学会関西支部 第506回講演会, 2018年12月, 日本語, 神戸大学, 国内会議

    口頭発表(一般)

  • セミの抜け殻が植物の生育に及ぼす影響

    梅澤高徳, 坂本克彦

    日本農芸化学会関西支部 第506回講演会, 2018年12月, 日本語, 神戸大学, 国内会議

    口頭発表(一般)

  • 寄主のJHA処理によるギンケハラボソコマユバチの大型化

    岡澤圭祐, 坂本克彦, 前藤 薫

    日本昆虫学会第78回大会, 2018年09月, 日本語, 名城大学, 国内会議

    ポスター発表

  • Detection of gene expression for photopigments in the Onchidium neurons.

    Takako NISHI, Katsuhiko SAKAMOTO

    JSCPB 2017 Fukuoka, 2017年11月, 日本語, 福岡大学, 国内会議

    ポスター発表

  • 昆虫におけるP450遺伝子の発現に及ぼす摂食の影響

    岩井酉樹, 坂本克彦

    西日本応用動物昆虫研究会・日本昆虫学会中国支部 平成29年度合同例会, 2017年10月, 日本語, 神戸大学, 国内会議

    口頭発表(一般)

  • 寄主のJHA処理理によるギンケハラボソコマユバチの⼤型化

    岡澤圭祐, 前藤 薫, 坂本克彦

    平成29年度西日本応用動物昆虫研究会・日本昆虫学会中国支部合同例会, 2017年10月, 日本語, 神戸大学, 国内会議

    口頭発表(一般)

  • セミの抜け殻が植物の生育に及ぼす影響

    梅澤高徳, 坂本克彦

    西日本応用動物昆虫研究会・日本昆虫学会中国支部 平成29年度合同例会, 2017年10月, 日本語, 神戸大学, 国内会議

    口頭発表(一般)

  • チョウ目昆虫幼虫の農薬感受性リズム制御機構の解明

    江木 雄一, 坂本 克彦

    日本農芸化学会関西支部 第487回講演会, 2014年12月, 日本語, 日本農芸化学会関西支部, 神戸大農学部, 国内会議

    口頭発表(一般)

  • チョウ目昆虫幼虫の農薬感受性リズムの解析

    江木 雄一, 坂本 克彦

    日本昆虫学会近畿支部2014年度大会, 2014年12月, 日本語, 日本昆虫学会近畿支部, 大阪市立自然史博物館, 国内会議

    口頭発表(一般)

  • サクサン蛹の休眠覚醒における光周性にはメラトニンが関与する

    江木 雄一, 王 秋実, 坂本 克彦

    第21回日本時間生物学会学術大会, 2014年11月, 日本語, 日本時間生物学会, 九州大学医学部百年講堂, 国内会議

    ポスター発表

  • Melatonin pathway transmits information to terminate pupal diapause and functions as a photoperiodic counter in the oak silkmoth, Antheraea pernyi.

    Yuichi EGI, Qiushi WANG, Kazuki Sakamoto

    JSC International Symposium, 2014年11月, 日本語, 日本時間生物学会, 九州大学医学部百年講堂, 国際会議

    ポスター発表

  • マイクロアレイ解析によるカイコ休眠制御遺伝子の網羅的検索

    江木 雄一, 秋友 紫苑, 坂本 克彦

    日本農芸化学会関西支部 第485回講演会, 2014年07月, 日本語, 日本農芸化学会関西支部, 大阪府立大学学術交流会館, 国内会議

    口頭発表(一般)

  • 寄生蜂ギンケサムライコマユバチの歩行活動における概日時計の制御

    西村 卓真, 藤井 智浩, 坂本 克彦, 前藤 薫

    第58回日本応用動物昆虫学会大会, 2014年03月, 日本語, 国内会議

    ポスター発表

  • マイクロアレイ解析によるカイコ光周性制御遺伝子の網羅的解析.

    秋友 紫苑, 江木 雄一, 坂本 克彦

    日本昆虫学会近畿支部2013年度大会・日本鱗翅学会近畿支部第148回例会 合同大会, 2013年12月, 日本語, 大阪(大阪市立自然史博物館), 国内会議

    口頭発表(一般)

  • サクサン蛹の休眠覚醒における光周性にはメラトニンとドーパミンが関与する

    王 秋実, 江木 雄一, 大石 勝隆, 竹田 真木生, 坂本 克彦

    第57回日本応用動物昆虫学会大会, 2013年03月, 日本語, 藤沢(日本大学生物資源科学科), 国内会議

    口頭発表(一般)

  • 休眠制御可能な2化性カイコ系統の選別

    江木 雄一, 竹田 真木生, 坂本 克彦

    日本応用動物昆虫学会中国支部・日本昆虫学会中国支部 平成24年度合同例会, 2012年10月, 日本語, 岡山(岡山大学50周年記念館), 国内会議

    口頭発表(一般)

  • 昆虫の休眠制御機構解明への挑戦

    坂本 克彦

    日本蚕糸学会 平成24年度蚕糸・昆虫機能利用学術講演会‐日本蚕糸学会第82回大会‐, 2012年03月, 日本語, 福岡(九州大学箱崎キャンパス), 国内会議

    口頭発表(一般)

  • 断頭カイコ幼虫における光受容.

    農端 洋行, 竹田 真木生, 坂本 克彦

    日本昆虫学会近畿支部2011年度大会・日本鱗翅学会近畿支部第144回例会 合同大会, 2011年12月, 日本語, 大阪(大阪市立自然史博物館), 国内会議

    口頭発表(一般)

  • 昆虫の休眠制御因子の検索

    農端 洋行, 竹田 真木生, 坂本 克彦

    日本農芸化学会関西支部 第472回講演会, 2011年12月, 日本語, 神戸(神戸大学農学部), 国内会議

    口頭発表(一般)

  • 昆虫の休眠制御機構解明への挑戦

    坂本 克彦

    平成23年度日本応用動物昆虫学会中国支部・日本昆虫学会中国支部合同例会, 2011年10月, 日本語, 神戸(神戸大学農学部), 国内会議

    口頭発表(一般)

  • カイコ幼虫末梢組織における時計遺伝子発現リズム.

    農端 洋行, 竹田 真木生, 坂本 克彦

    日本応用動物昆虫学会中国支部・日本昆虫学会中国支部 平成23年度合同例会, 2011年10月, 日本語, 神戸(神戸大学農学部), 国内会議

    口頭発表(一般)

  • 昆虫の休眠制御因子の検索

    農端 洋行, 竹田 真木生, 坂本 克彦

    第17回日本野蚕学会, 2011年09月, 日本語, 京都(京都工芸繊維大学), 国内会議

    口頭発表(一般)

  • 哺乳類の体内時計システム:中枢時計と末梢時計.

    坂本 克彦

    兵庫バイオテクノロジー研究会第78回定例会, 2010年03月, 日本語, 神戸(神戸大学農学部キャンパス), 国内会議

    口頭発表(一般)

  • 哺乳類の体内時計システム:中枢時計と末梢時計.

    坂本 克彦

    第2回神戸大学バイオサイエンス研究会・若手交流会, 2010年02月, 日本語, 神戸(神戸大学医学部キャンパス), 国内会議

    口頭発表(一般)

共同研究・競争的資金等の研究課題

  • 坂本 克彦

    学術研究助成基金助成金/基盤研究(C), 2017年04月 - 2020年03月, 研究代表者

    競争的資金

  • 哺乳類概日時計の位相調節関連タンパク質のプロテオーム解析による検索

    坂本 克彦

    日本学術振興会, 科学研究費助成事業, 基盤研究(C), 株式会社三菱化学生命科学研究所, 2007年 - 2008年

    本研究では、哺乳類の脳内時計中枢である視交叉上核由来の細胞株を用いて、体内時計の時刻同調(時計の針の時刻合わせ)機構に関与するタンパク質の検索を試みた。時計の針を動かす薬剤刺激を与えたときに発現量が変化するタンパク質を検索し、得られたタンパク質の機能阻害実験をおこなったところ、時刻同調機構に関与する可能性があるタンパク質を複数種類得ることができた。体内時計の入力系メカニズムの解明に結びつく発見となった。