論文 - 内田 勝久
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Nagashima H., Kuraku S., Uchida K., Kawashima-Ohya Y., Narita Y., Kuratani S.
Vertebrate Paleobiology and Paleoanthropology ( 9789400743083 ) 37 - 50 2013年
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Vertebrate Paleobiology and Paleoanthropology
© Springer Science+Business Media Dordrecht 2013. The turtle shell is comprised of a dorsal carapace and a ventral plastron, and is an autapomorphy of this group. The carapace consists of the vertebral column and ribs as well as a specialized dermis. The formation of the shell is accompanied by a change in the spatial relationship of the ribs and the pectoral girdle. Because of this rearrangement, the turtle shell has been regarded as an example of an evolutionary novelty. Understanding the changes behind this developmental repatterning will help us elucidate the evolutionary history of turtles. The change has been attributed to a deflected pattern of development of the ribs, which in normal tetrapods grow ventrally into the lateral body wall. In turtles, they grow laterally toward the primordium of the carapacial margin, called the carapacial ridge (CR), while remaining in the axial part of the embryonic body. Based on a similarity in histological configuration, the CR has been thought to possess inductive activity for rib growth, as seen in the apical ectodermal ridge of the amniote limb bud. The CR does not function as a guidance cue for rib progenitor cells but rather functions in the marginal growth of the carapacial primordium, resulting in fanned-out growth of the ribs. This peripheral and concentric expansion of the axial domain makes the lateral body wall fold inward, while the ribs cover the pectoral girdle. The turtle ribs develop along the muscle plate as in other amniotes, and do not take a different trajectory from that in other amniotes, unlike the scenario hypothesized previously. This folding enables turtles to change the apparent spatial relationships between the ribs and the pectoral girdle without altering their topological alignment and body plan as amniotes. This developmental sequence of the modern turtles aligns with a stepwise evolutionary process in the group, which is supported by the anatomy of a recently discovered fossil species, Odontochelys.
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Regulation of growth hormone (GH) receptor (GHR1 and GHR2) mRNA level by GH and metabolic hormones in primary cultured tilapia hepatocytes. 査読あり
Pierce AL, Breves JP, Moriyama S, Uchida K, Grau EG.
General and Comparative Endocrinology 179 ( 1 ) 22 - 29 2012年10月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Induction of sexual maturation of the female honeycomb grouper, Epinephelus merra, in the non-breeding season by modulating environmental factors with GnRH analogue implantation 査読あり
Kanemaru T, Nakamura M, Murata R, Kuroki K, Horie H, Uchida K, Senthilkumaran B, Kagawa H
Aquaculture 358-359 85 - 91 2012年7月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Body plan of turtles: an anatomical, developmental and evolutionary perspective. 招待あり 査読あり
Nagashima H, Kuraku S, Uchida K, Kawashima-Ohya Y, Narita Y, Kuratani S
Anatomical Science International 87 ( 1 ) 1 - 13 2011年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Characterization of novel RFamide peptides in the central nervous system of the brown hagfish: isolation, localization, and functional analysis. 査読あり
Osugi T, Uchida K, Nozaki M, Tsutsui K
Endocrinology 152 ( 11 ) 4252 - 4264 2011年8月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Evolutionary origin of a functional gonadotropin in the pituitary of the hagfish 招待あり
Uchida K, Moriyama S, Sower S.A, Nozaki M.
Internal Symposium on Reproductive Physiology of Fish 4 ( S8 ) 4 - 5 2011年8月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
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最も原始的な脊椎動物・ヌタウナギの下垂体から単離された生殖腺刺激ホルモンとその進化的起源
内田 勝久
比較内分泌学 = Comparative endocrinology 37 ( 140 ) 32 - 36 2011年2月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Japan Society for Comparative Endocrinology
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Uchida K., Moriyama S., Chiba H., Shimotani T., Honda K., Miki M., Takahashi A., Sower S., Nozaki M.
Proceedings of the National Academy of Sciences of the United States of America 107 ( 36 ) 15832 - 15837 2010年9月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Proceedings of the National Academy of Sciences of the United States of America
Hagfish, which lack both jaws and vertebrae, are considered the most primitive vertebrate known, living or extinct. Hagfish have long been the enigma of vertebrate evolution not only because of their evolutionary position, but also because of our lack of knowledge on fundamental processes. Key elements of the reproductive endocrine system in hagfish have yet to be elucidated. Here, the presence and identity of a functional glycoprotein hormone (GPH) have been elucidated from the brown hagfish Paramyxine atami. The hagfish GPH consists of two subunits, α and β, which are synthesized and colocalized in the same cells of the adenohypophysis. The cellular and transcriptional activities of hagfish GPHα and -β were significantly correlated with the developmental stages of the gonad. The purified native GPH induced the release of gonadal sex steroids in vitro. From our phylogenetic analysis, we propose that ancestral glycoprotein α-subunit 2 (GPA2) and β-subunit 5 (GPB5) gave rise to GPHα and GPHβ of the vertebrate glycoprotein hormone family, respectively. The identified hagfish GPHα and -β subunits appear to be the typical gnathostome GPHα and -β subunits based on the sequence and phylogenetic analyses. We hypothesize that the identity of a single functional GPH of the hagfish, hagfish GTH, provides critical evidence for the existence of a pituitary-gonadal system in the earliest divergent vertebrate that likely evolved from an ancestral, prevertebrate exclusively neuroendocrine mechanism by gradual emergence of a previously undescribed control level, the pituitary, which is not found in the Protochordates.
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Evolutionary origin of a functional gonadotropin in the pituitary of the most primitive vertebrate, hagfish. 査読あり
Uchida K., Moriyama S., Chiba H., Simotani T., Honda K., Miki M., Takahashi A., Sower S.A., Nozaki M.
Proceedings of the National Academy of Sciences of the United State of America 107 ( 36 ) 15832 - 15837 2010年8月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Furukawa F., Watanabe S., Kaneko T., Uchida K.
General and Comparative Endocrinology 166 ( 3 ) 549 - 555 2010年5月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
Mozambique tilapia, Oreochromis mossambicus, is easily acclimated to highly acidic water, and thus presents a useful model to unravel endocrine regulation of adaptation to acidic water in fish. We analyzed gene expression of somatolactin (sl), growth hormone (gh) and prolactin (prl), in the pituitary gland and size distribution of mitochondria-rich (MR) cells in the gills after transfer from normal freshwater (FW, pH 7.2) to acidified freshwater (AW, pH 3.5). Plasma osmolality drastically decreased until 2. days after transfer to AW, but had restored to normal after 1. week of acclimation, and this confirmed the excellent acid tolerance of tilapia. Expression levels of sl, gh and prl were all up-regulated during short-term exposure to AW. The expression of sl remained elevated up to 7. days after transfer; the expression of gh and prl was back to initial levels at that time. These findings point to an important and specific role of SL in adaptation to acid water in this tilapia, although temporal contribution of GH and PRL cannot be ruled out. The size distribution of branchial MR cells changed drastically during acclimation to AW. The mean MR cell size was 1.5-fold larger in the fish exposed to AW for 7. da ys compared to controls in FW. The gills and their MR cells are a likely site of important acid-base regulation, and SL may change ion-transport functions of MR cells to correct plasma osmotic balance disturbed by acid exposure. © 2010 Elsevier Inc.
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Uchida K., Moriyama S., Breves J., Fox B., Pierce A., Borski R., Hirano T., Gordon Grau E.
General and Comparative Endocrinology 161 ( 2 ) 162 - 170 2009年4月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
Somatolactin (SL) is a member of the growth hormone (GH)/prolactin (PRL) family of pituitary hormones, and is found in a variety of teleost species. Somatolactin is thought to be involved in a wide range of physiological actions, including reproduction, stress response, the regulation of Ca 2+ and acid-base balance, growth, metabolism, and immune response. We report here on the cDNA structure of SL from the pituitary of Mozambique tilapia, Oreochromis mossambicus, and its gene expression in response to seawater acclimation, stress, and fasting. Tilapia SL cDNA (1573 bp long) encoded a prehormone of 230 amino acids. Sequence analysis of purified SL revealed that the prehormone is composed of a signal peptide of 23 amino acids and a mature protein of 207 amino acids, which has a possible N-glycosylation site at position 121 and seven Cys residues. Tilapia SL shows over 80% amino acid identity with SLα of advanced teleosts such as medaka and flounder, and around 50% identity with SLβ of carp and goldfish. Acclimation to seawater had no effect on pituitary expression of SL or on hepatic expression of the putative tilapia SL receptor (GHR1). By contrast, seawater acclimation resulted in significant increases in pituitary GH expression and in hepatic expression of tilapia GH receptor (GHR2). Confinement stress had no effect on pituitary expression of either SL or GH, or on hepatic expression of GHR1, whereas a significant increase was seen in GHR2 expression in the liver. Fasting for 4 weeks resulted in significant reductions in SL transcripts both in fresh water and seawater. It is highly likely that SL is involved in metabolic processes in tilapia along with the GH/IGF-I axis. © 2009 Elsevier Inc. All rights reserved.
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Radiolarian faunal characteristics in surface-subsurface waters of the Japan Sea off Tassha, Sado Island, central Japan in June 2007: inflowing radiolarians on the Tsushima Warm Current.
Kurihara T., Uchida K., Shimotani T., Matsuoka A.
Science Reports of Niigata University (Geology) 23 65 - 74 2008年3月
記述言語：英語 掲載種別：研究論文（大学，研究機関等紀要）
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Magdeldin S., Uchida K., Hirano T., Grau E., Abdelfattah A., Nozaki M.
Fisheries Science 73 ( 5 ) 1025 - 1034 2007年10月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Fisheries Science
Hormonal control of growth was examined in juvenile Mozambique tilapia Oreochromis mossambicus under different environmental salinities. When juvenile tilapia were acclimated to fresh water (FW) or to full-strength sea water (SW) for 3 weeks, growth rate of the SW-acclimated fish doubled compared to FW fish. Pituitary mRNA levels of growth hormone (GH) were significantly higher in SW-adapted tilapia compared with FW fish, while the gene expression of prolactin (PRL 188 and PRL 177 ) in SW fish was lower than in the FW group. The release and synthesis of insulin-like growth factor-I (IGF-I) were significantly elevated in the SW fish. This indicates that the GH/IGF-I axis is up-regulated in juvenile tilapia in SW and likely leads to the observed elevation in growth. Transfer of the juveniles from FW to 70% SW or vice versa for 2 weeks had no effect on growth rate. On the other hand, GH transcripts as well as hepatic IGF-I mRNA levels increased significantly after transfer of the FW-acclimated fish to 70% SW, while PRL 188 mRNA levels were significantly elevated after transfer of the 70% SW fish to FW. Our findings indicate that the GH/IGF-I axis plays important roles both in growth and in osmoregulation in juvenile tilapia in SW. © 2007 Japanese Society of Fisheries Science.
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Nozaki M., Shimotani T., Uchida K.
Cell and Tissue Research 328 ( 3 ) 563 - 572 2007年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Cell and Tissue Research
The pituitary system of the hagfish remains an enigma. The present study has aimed to detect possible adenohypophysial hormones in the pituitary gland of the brown hagfish, Paramyxine atami, by means of immunohistochemistry in combination with lectin histochemistry. Rabbit antisera raised against ovine luteinizing hormone (LH)β, proopiomelanocortin (POMC)-related peptides, and the growth hormone/prolactin family of tetrapod and fish species were used, and 25 kinds of lectins were tested. Three different types of adenohypophysial cells were revealed in the pituitary of brown hagfish. The first was stained with both anti-ovine LHβ and several D-mannose-binding lectins, such as Lens culinaris agglutinin and Pisum sativum agglutinin. This cell type predominated in the adenohypophysis in adults with developing gonads and thus appeared to be involved in the regulation of gonadal functions. The second was negative for anti-ovine LHβ but was stained with several N-acetylglucosamine-binding lectins, such as wheat germ agglutinin and Lycopersicon esculentum lectin. This cell type exhibited a weak positive reaction with anti-lamprey adrenocorticotropin (ACTH) and thus appeared to be related to POMC-like cells. The second cell type was found in the adenohypophysis regardless of the developmental state of the gonads. The third cell type was negative for both antisera and lectins. Since this cell type was numerous in juveniles and adults without developing gonads, most cells of this type were probably undifferentiated. These findings suggest that GTH and ACTH are major adenohypophysial hormones in the hagfish. © 2007 Springer-Verlag.
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Nagashima H., Kuraku S., Uchida K., Ohya Y., Narita Y., Kuratani S.
Development 134 ( 12 ) 2219 - 2226 2007年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Development
The chelonian carapace is composed of dorsolaterally expanded ribs; an evolutionary change in the rib-patterning program is assumed to be related to this novelty. Turtle embryos exhibit a longitudinal ridge called the carapacial ridge (CR) on the flank, and its histological resemblance to the apical ectodermal ridge of the limb bud implies its inductive activity in the unique patterning of the ribs. We studied the Chinese soft-shelled turtle, Pelodiscus sinensis, and confirmed by labeling with a lipophilic dye, Dil, that the CR contains the somite-derived dermis and that it is a unique structure among amniotes. Using electroporation of a dominant-negative form of LEF-1, the CR-specific gene, we showed that CR-specific genes function in the growth and maintenance of the CR. Microcauterization or implantation of the CR did not change the dorsoventral pattern of the ribs, and only their fan-shaped pattern was arrested by CR removal. We conclude that the CR is a true embryonic novelty among amniotes and, because of the specific expression of regulatory genes, it functions in the marginal growth of the carapacial primordium, thereby inducing the fan-shaped arrangement of the ribs.
DOI： 10.1242/dev.002618
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Gonadotropin-like and adrenocorticotropin-like cells in the pituitary gland of hagfish, Paramyxine atami: immunohistochemistry in combination with lectin histochemistry. 査読あり
Nozaki M., Shimotani T., Uchida K.
Cell and Tissue Research 328 563 - 572 2007年3月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Radiolarian faunas and water properties in surface and subsurface waters of the Japan Sea in September 2005 off Tassha, Sado Island, central Japan.
Kurihara T., Uchida K., Shimotani S., Matsuoka A.
Science Reports of Niigata University (Geology) 22 35 - 42 2007年3月
記述言語：英語 掲載種別：研究論文（大学，研究機関等紀要）
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Identification of gonadotropin producing cells in the adenohypophysis of brown hagfish, Paramyxine atami.
Honda K., Uchida K., Shimotani S., Moriyama S., Nozaki M.
Proceedings of The Japan Society for Comparative Endocrinology 21 52 - 52 2006年12月
記述言語：英語 掲載種別：研究論文（その他学術会議資料等）
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Identification of sea lamprey GTHβ-like cDNA and its evolutionary implications
Sower S., Moriyama S., Kasahara M., Takahashi A., Nozaki M., Uchida K., Dahlstrom J., Kawauchi H.
General and Comparative Endocrinology 148 ( 1 ) 22 - 32 2006年8月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
We have identified the first and perhaps only gonadotropin β-like protein by cDNA cloning in sea lamprey, a member of the oldest lineage of vertebrates, the agnathans. Two pituitary gonadotropins (GTHs: follicle-stimulating hormone (FSH) and luteinizing hormone (LH)) have been identified in representative species of all classes of vertebrates except the agnathans. The present study was undertaken to identify GTH in sea lamprey, Petromyzon marinus, to gain a further understanding of the origin and evolution of reproductive pituitary hormones and their respective genes in vertebrates. Sea lamprey preGTHβ-like cDNA was cloned from a plasmid cDNA library using an expressed sequence tag analysis. The preGTHβ-like cDNA encoded 150 amino acids, in which the GTHβ-like protein consisted of 134 amino acid residues. Sea lamprey GTHβ-like protein contained 12 Cys residues and two N-glycosylation sites at homologous positions to those of FSHβ and LHβ. The region of the molecule that has been proposed to control receptor binding specificity (i.e., the region between the 10th and 12th Cys residues) suggests that the proposed heterodimer would be more like a FSH than a LH. Sea lamprey GTHβ-like protein-producing cells were identified immunocytochemically in the ventral part of the proximal pars distalis of pituitary using antiserum prepared against a synthetic peptide of preGTHβ-like protein (52-68). Intraperitoneal administration of sea lamprey GnRH-I and -III at 100 μg/g body weight (twice at a 24 h interval) increased expression of GTHβ-like protein in the pituitary of adult female sea lamprey during the final maturational period. Thus, these results are the first to demonstrate the presence of a single GTH-like system in lampreys. Because the sea lamprey GTHβ-like protein is a clear out-group compared to those of the LH and FSH family based on phylogenic analysis, we propose that an ancestral glycoprotein hormone gave rise to only one GTH in lampreys and to the glycoprotein hormone family that gave rise to LH, FSH, and TSH during the early evolution of gnathostomes. © 2005 Elsevier Inc. All rights reserved.
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Miki M., Shimotani T., Uchida K., Hirano S., Nozaki M.
General and Comparative Endocrinology 148 ( 1 ) 15 - 21 2006年8月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
Since hagfish are members of the most primitive group of living vertebrates, studies on their reproduction are indispensable for understanding phylogenetic aspects of vertebrate reproductive system. Nevertheless, our knowledge of the reproductive physiology of the hagfish, especially of the pituitary-gonadal axis, is almost completely lacking. In the present study, the relationship between the amount of immunoreactive gonadotropin (GTH)-like material in the pituitary gland and gonadal conditions was examined in the brown hagfish, Paramyxine atami. First, pituitary sections were stained immunohistochemically with anti-ovine LHβ, and the degrees of the accumulation of GTH-like material were compared among three different groups of gonadal conditions; juveniles and adults with and without developing gonads. Immunoreactive GTH-like material was heavily accumulated in adults with developing gonads, whereas it was not or only weakly accumulated in juveniles or adults without developing gonads. Thus, there was a strong positive correlation between the amount of GTH-like material and gonadal conditions. Second, effect of estradiol benzoate on GTH-like material was examined using three groups of juvenile hagfish: initial control, sham control, and experimental animals. Experimental animals received estradiol benzoate resolved in sesame oil intraperitoneally every third day for 1 month, whereas sham control animals received the same doses of sesame oil. GTH-like material was heavily or moderately accumulated in most estrogen-treated animals, whereas it was not or weakly accumulated in initial or sham control animals. Thus, estrogen treatment in juvenile hagfish resulted in the large increase in the amount of GTH-like material. From these results, it is suggested the presence of not only GTH but also the hypophysial-gonadal feedback system in the hagfish. © 2006 Elsevier Inc. All rights reserved.