Faculty Profiles - SAKAMOTO Tatsuya

Hyperosmotic tolerance of adult fish and early embryos are determined by discrete, single loci in the genus Oryzias

Other Link： http://link.springer.com/article/10.1007/s10846-018-0970-x/fulltext.html

Discussion about Reproductive Mechanism of Eel-Grass（Zostera marina）

Tomio FUKUDA, Yasutoshi KOHDA, Masatoshi MIZUTANI, Tatsuya SAKAMOTO

J Kibi Int Univ Res Inst Health Welfare. (29),1-20 (2019-03-22) 2019.3

'Central' Actions of Corticosteroid Signaling Suggested by Constitutive Knockout of Corticosteroid Receptors in Small Fish

Sakamoto T, Sakamoto H

Nutrients. 2019 Mar 13;11(3). pii: E611. doi: 10.3390/nu11030611 2019

雄ラットにおける性行動への内側視索前野の性的二型核の関与

前嶋翔, 野村黎, 高浪景子, 高浪景子, 坂本竜哉, 坂本浩隆

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 44th 2019

Taijun Myosho, Hideya Takahashi, Kento Yoshida, Tadashi Sato, Satoshi Hamaguchi, Tatsuya Sakamoto, Mitsuru Sakaizumi

Scientific Reports 8 ( 1 ) 2018.12

The Amphibious Mudskipper: A Unique Model Bridging the Gap of Central Actions of Osmoregulatory Hormones Between Terrestrial and Aquatic Vertebrates. Reviewed

Katayama K, Sakamoto T, Takanami K, Takei Y

Frontiers in Physiology, 9 1112 2018.8

Characterization of distinct ovarian isoform of crustacean female sex hormone in the kuruma prawn Marsupenaeus japonicus

Naoaki Tsutsui, Sayaka Kotaka, Tsuyoshi Ohira, Tatsuya Sakamoto

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY 217 7 - 16 2018.3

Language：English Publisher：ELSEVIER SCIENCE INC

The eyestalk hormone, crustacean female sex hormone (CFSH), regulates the development of female secondary sexual characteristics in the blue crab Callinectes sapidus. After its discovery, several CFSH gene orthologs have been identified in some species of the suborder Pleocyemata as well. Similarly, in species of another suborder (Dendrobranchiata), an ortholog (Maj-CFSH) has been characterized as an eyestalk factor expressed in both females and males of the kuruma prawn, Marsupenaeus japonicus. In this study, another novel CFSH isoform was identified in the same species using cDNA cloning, expression analysis, and recombinant protein production. The isoform has "CFSH-family" structural characteristics but is dominantly expressed in the ovary, and was therefore designated as Maj-CFSH-ov. Its mRNA and protein levels in vitellogenic ovaries are higher than those in non-vitellogenic ovaries. In the vitellogenic ovary, both mRNA and protein expression of Maj-CFSH-ov are localized to oogonia and previtellogenic oocytes that occupy a small portion of vitellogenic ovaries, but not to the major developing oocytes. A vitellogenesis-inhibiting peptide of M. japonicus (Pej-SGP-I) reduced the expression of vitellogenin in incubated ovarian fragments, but not that of Maj-CFSH-ov. These results indicate that M. japonicus possesses two CFSH isoforms that are derived from distinct tissues, the central X-organ/sinus gland complex and peripheral ovaries. The expression profile of Maj-CFSH-ov suggests its involvement in some reproductive process other than vitellogenesis.

DOI： 10.1016/j.cbpa.2017.12.009

Web of Science

Analyzing the effects of co-expression of chick (Gallus gallus) melanocortin receptors with either chick MRAP1 or MRAP2 in CHO cells on sensitivity to ACTH(1–24) or ACTH(1–13)NH2: Implications for the avian HPA axis and avian melanocortin circuits in the hypothalamus

Alexa L. Thomas, Fumihiko Maekawa, Takaharu Kawashima, Hirotaka Sakamoto, Tatsuya Sakamoto, Perry Davis, Robert M. Dores

General and Comparative Endocrinology 256 50 - 56 2018.1

Language：English Publisher：Academic Press Inc.

In order to better understand the roles that melanocortin receptors (cMCRs) and melanocortin-2 receptor accessory proteins (cMRAP1 and cMRAP2) play in the HPA axis and hypothalamus, adrenal gland and hypothalamus mRNA from 1 day-old white leghorn chicks (Gallus gallus), were analyzed by real-time PCR. mRNA was also made for kidney, ovary, and liver. Mrap1 mRNA could be detected in adrenal tissue, but not in any of the other tissues, and mrap2 mRNA was also detected in the adrenal gland. Finally, all five melanocortin receptors mRNAs could be detected in the adrenal gland
mc2r and mc5r mRNAs were the most abundant. To evaluate any potential interactions between MRAP1 and the MCRs that may occur in adrenal cells, individual chick mcr cDNA constructs were transiently expressed in CHO cells either in the presence or absence of a chick mrap1 cDNA, and the transfected cells were stimulated with hACTH(1–24) at concentrations ranging from 10−13 M to 10−6 M. As expected, MC2R required co-expression with MRAP1 for functional expression
whereas, co-expression of cMC3R with cMRAP1 had no statistically significant effect on sensitivity to hACTH(1–24). However, co-expression of MC4R and MC5R with MRAP1, increased sensitivity for ACTH(1–24) by approximately 35 fold and 365 fold, respectively. However, co-expressing of cMRAP2 with these melanocortin receptors had no effect on sensitivity to hACTH(1–24). Since the real-time PCR analysis detected mrap2 mRNA and mc4r mRNA in the hypothalamus, the interaction between cMC4R and cMRAP2 with respect to sensitivity to ACTH(1–13)NH2 stimulation was also evaluated. However, no effect, either positive or negative, was observed. Finally, the highest levels of mc5r mRNA were detected in liver cells. This observation raises the possibility that in one-day old chicks, activation of the HPA axis may also involve a physiological response from liver cells.

DOI： 10.1016/j.ygcen.2017.09.002

Drinking by amphibious fish: convergent evolution of thirst mechanisms during vertebrate terrestrialization. International journal

Yukitoshi Katayama, Tatsuya Sakamoto, Kazuhiro Saito, Hirotsugu Tsuchimochi, Hiroyuki Kaiya, Taro Watanabe, James T Pearson, Yoshio Takei

Scientific reports 8 ( 1 ) 625 - 625 2018.1

Language：English

Thirst aroused in the forebrain by angiotensin II (AngII) or buccal drying motivates terrestrial vertebrates to search for water, whereas aquatic fish can drink surrounding water only by reflex swallowing generated in the hindbrain. Indeed, AngII induces drinking through the hindbrain even after removal of the whole forebrain in aquatic fish. Here we show that AngII induces thirst also in the amphibious mudskipper goby without direct action on the forebrain, but through buccal drying. Intracerebroventricular injection of AngII motivated mudskippers to move into water and drink as with tetrapods. However, AngII primarily increased immunoreactive c-Fos at the hindbrain swallowing center where AngII receptors were expressed, as in other ray-finned fish, and such direct action on the forebrain was not found. Behavioural analyses showed that loss of buccal water on land by AngII-induced swallowing, by piercing holes in the opercula, or by water-absorptive gel placed in the cavity motivated mudskippers to move to water for refilling. Since sensory detection of water at the bucco-pharyngeal cavity like 'dry mouth' has recently been noted to regulate thirst in mammals, similar mechanisms seem to have evolved in distantly related species in order to solve osmoregulatory problems during terrestrialization.

DOI： 10.1038/s41598-017-18611-4

Nemertean and phoronid genomes reveal lophotrochozoan evolution and the origin of bilaterian heads

Yi-Jyun Luo, Miyuki Kanda, Ryo Koyanagi, Kanako Hisata, Tadashi Akiyama, Hirotaka Sakamoto, Tatsuya Sakamoto, Noriyuki Satoh

Nature Ecology and Evolution 2 ( 1 ) 141 - 151 2018.1

Language：English Publisher：Nature Publishing Group

Nemerteans (ribbon worms) and phoronids (horseshoe worms) are closely related lophotrochozoans - a group of animals including leeches, snails and other invertebrates. Lophotrochozoans represent a superphylum that is crucial to our understanding of bilaterian evolution. However, given the inconsistency of molecular and morphological data for these groups, their origins have been unclear. Here, we present draft genomes of the nemertean Notospermus geniculatus and the phoronid Phoronis australis, together with transcriptomes along the adult bodies. Our genome-based phylogenetic analyses place Nemertea sister to the group containing Phoronida and Brachiopoda. We show that lophotrochozoans share many gene families with deuterostomes, suggesting that these two groups retain a core bilaterian gene repertoire that ecdysozoans (for example, flies and nematodes) and platyzoans (for example, flatworms and rotifers) do not. Comparative transcriptomics demonstrates that lophophores of phoronids and brachiopods are similar not only morphologically, but also at the molecular level. Despite dissimilar head structures, lophophores express vertebrate head and neuronal marker genes. This finding suggests a common origin of bilaterian head patterning, although different heads evolved independently in each lineage. Furthermore, we observe lineage-specific expansions of innate immunity and toxin-related genes. Together, our study reveals a dual nature of lophotrochozoans, where conserved and lineage-specific features shape their evolution.

DOI： 10.1038/s41559-017-0389-y

Visual Docking against Bubble Noise with Three-dimensional Perception Using Dual-eye Cameras

Khin Lwin, Naoki Mukada, Myo Myint, Daiki Yamada, Akira Yanou, Takayuki Matsno, Kazuhiro Saitou, Waichiro Godou, Tatsuya Sakamoto, Mamoru Minami

IEEE Journal of Oceanic Engineering DOI (identifier) 10.1109/JOE.2018.2871651 2018

Robust Visual Servoing against Air Bubble Noise with

Khin Lwin, Naoki Mukada, Myo Myint, Daiki Yamada, Akira Yanou, Takayuki Matsno, Kazuhiro Saitou, Waichiro Godou, Tatsuya Sakamoto, Mamoru Minami

Journal of Advanced Mechanical Design, Systems, and Manufacturing 2018

Molecular cloning and tissue distribution analysis of corticosteroid receptor genes in two cartilaginous fishes, catshark (Elasmobranchii) and elephant fish (Holocephali)

Wataru Takagi, Tatsuya Sakamoto

Data in Brief 7 2018

A possible principal function of corticosteroid signaling that is conserved in vertebrate evolution: Lessons from receptor-knockout small fish

Tatsuya Sakamoto, Susumu Hyodo, Wataru Takagi

Journal of Steroid Biochemistry and Molecular Biology 2018

Language：English Publisher：Elsevier Ltd

Corticosteroid receptors are critical for homeostasis maintenance, but understanding of the principal roles of the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) throughout vertebrates is limited. Lines of constitutive GR-knockout zebrafish and MR-knockout medaka have recently been generated as the first adult-viable corticosteroid receptor-knockout animals, in contrast to the lethality of these receptor knockouts in mice. Here, we describe behavioral and physiological modifications following disruption of corticosteroid receptor function in these animal models. We suggest these data point toward a potentially conserved function of corticosteroid receptors in integrating brain-behavior and visual responses in vertebrates. Finally, we discuss how future work in cartilaginous fishes (Chondrichthyes) will further advance understanding of the unity and diversity of corticosteroid receptor function, since distinct orthologs of GR and MR derived from an ancestral corticoid receptor appear in these basal jawed vertebrates.

DOI： 10.1016/j.jsbmb.2018.02.011

Effects of Sex Steroids on the Spinal Gastrin-Releasing Peptide System Controlling Male Sexual Function in Rats. International journal

Takumi Oti, Keiko Takanami, Saya Ito, Takashi Ueda, Ken Ichi Matsuda, Mitsuhiro Kawata, Jintetsu Soh, Osamu Ukimura, Tatsuya Sakamoto, Hirotaka Sakamoto

Endocrinology 159 ( 4 ) 1886 - 1896 2018

Language：English

The gastrin-releasing peptide (GRP) system in the lumbosacral spinal cord controls male sexual function in rats. In contrast, in female rats, GRP neurons could scarcely be detected around puberty when circulating ovarian steroid hormones such as estradiol and progesterone levels are increasing. However, little information is available on feminizing or demasculinizing effects of ovarian steroids on the central nervous system in female puberty and adulthood. In this study, to visualize the spinal GRP neurons in vivo, we generated a GRP-promoter-Venus transgenic (Tg) rat line and studied the effects of the sex steroid hormones on GRP expression in the rat lumbar cord by examining the Venus fluorescence. In these Tg rats, the sexually dimorphic spinal GRP neurons controlling male sexual function were clearly labeled with Venus fluorescence. As expected, Venus fluorescence in the male lumbar cord was markedly decreased after castration and restored by chronic androgen replacement. Furthermore, androgen-induced Venus expression in the spinal cord of adult Tg males was significantly attenuated by chronic treatment with progesterone but not with estradiol. A luciferase assay using a human GRP-promoter construct showed that androgens enhance the spinal GRP system, and more strikingly, that progesterone acts to inhibit the GRP system via an androgen receptor-mediated mechanism. These results demonstrate that circulating androgens may play an important role in the spinal GRP system controlling male sexual function not only in rats but also in humans and that progesterone could be an important feminizing factor in the spinal GRP system in females during pubertal development.

DOI： 10.1210/en.2018-00043

Unique Model Bridging the Gap of Central Actions of Osmoregulatory Hormones

Katayama Y, Sakamoto T, Takanami K, Takei Y

Front Physiol. 2018 Aug 14;9:1112. 2018

Effects of Sex Steroids on the Spinal Gastrin-Releasing

Oti T, Takanami K, Ito S, Ueda T, Matsuda KI, Kawata M, Soh J, Ukimura O

Endocrinology. 2018 Apr 1;159(4):1886-1896 2018

A sexually dimorphic peptidergic system in the lower spinal cord controlling penile function in non-human primates

T. Ito, T. Oti, K. Takanami, K. Satoh, Y. Ueda, T. Sakamoto, H. Sakamoto

Spinal Cord 56 ( 1 ) 57 - 62 2018

Language：English Publisher：Nature Publishing Group

Study design: Experimental animal study. Objectives: Although a population of gastrin-releasing peptide (GRP) neurons in the lumbar spinal cord has an important role in erection and ejaculation in rats, little information exists on this GRP system in primates. To identify the male-specific GRP system in the primate spinal cord, we studied the lumbosacral cord in macaque monkeys as a non-human primate model. Setting: University laboratory in Japan. Methods: To determine the gene sequence of GRP precursors, the rhesus macaque monkey genomic sequence data were searched, followed by phylogenetic analysis. Subsequently, immunocytochemical analysis for GRP was performed in the monkey spinal cord. Results: We have used bioinformatics to identify the ortholog gene for GRP precursor in macaque monkeys. Phylogenetic analysis suggested that primate prepro-GRP is separated from that of other mammalian species and clustered to an independent branch as primates. Immunocytochemistry for GRP further demonstrated that male-dominant sexual dimorphism was found in the spinal GRP system in monkeys as in rodents. Conclusion: We have demonstrated in macaque monkeys that the GRP system in the lower spinal cord shows male-specific dimorphism and May have an important role in penile functions not only in rodents but also in primates.

DOI： 10.1038/sc.2017.105