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7. Hepatic estrogen-responsive genes relating to oogenesis in cutthroat trout (Oncorhynchus clarki): The transcriptional induction in primary cultured hepatocytes and the in vitro promoter transactivation in responses to estradiol-17β

Author

Nagata, Jun, primary, Mushirobira, Yuji, additional, Nishimiya, Osamu, additional, Yamaguchi, You, additional, Fujita, Toshiaki, additional, Hiramatsu, Naoshi, additional, Hara, Akihiko, additional, and Todo, Takashi, additional

Published
2021
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8. Changes in the Hepatic Expression of Three Vitellogenin Subtype Genes During Ovarian Development in Female White-Edged Rockfish (Sebastes taczanowskii)

Author

Nagata, Jun, primary, Wada, Satoru, additional, Nishimiya, Osamu, additional, Wu, Meiqin, additional, Mushirobira, Yuji, additional, Yamaguchi, Yo, additional, Yokono, Takanori, additional, Kawasaki, Takuma, additional, Matsubara, Takahiro, additional, Todo, Takashi, additional, Hara, Akihiko, additional, and Hiramatsu, Naoshi, additional

Published
2021
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11. Hepatic estrogen-responsive genes relating to oogenesis in cutthroat trout (Oncorhynchus clarki) : The transcriptional induction in primary cultured hepatocytes and the in vitro promoter transactivation in responses to estradiol-17 beta

Author

Nagata, Jun, Mushirobira, Yuji, Nishimiya, Osamu, Yamaguchi, You, Fujita, Toshiaki, Hiramatsu, Naoshi, Hara, Akihiko, Todo, Takashi, Nagata, Jun, Mushirobira, Yuji, Nishimiya, Osamu, Yamaguchi, You, Fujita, Toshiaki, Hiramatsu, Naoshi, Hara, Akihiko, and Todo, Takashi

Abstract

Estradiol-17 beta (E2) regulates transcription of estrogen-responsive genes via estrogen receptors (Esr). In many teleost species, choriogenin (chg), vitellogenin (vtg) and esr genes are transactivated by E2 in the liver. This study aimed i) to compare expression properties of all subtypes of these genes (chg: chgH alpha, chgH beta, chgL; vtg: vtgAs, vtgC; esr: esr1a, esr1b, esr2a, esr2b) in response to estrogen stimulation, and ii) to confirm how each of four Esr subtypes is involved in the transcriptional regulation of these estrogen-responsive genes in cutthroat trout hepatocytes. In hepatocytes in primary culture, all chg and vtg subtype mRNA levels, and those of esr1a, were increased by E2 treatment (10(-6) M) at 24 and 72 h post initiation (hpi), but esr1b, esr2a and esr2b mRNA levels were not. Treatment of hepatocytes with various concentrations of E2 (10(-11)-10(-6) M) induced dose-dependent increases in the levels of all chg and vtg subtype mRNAs at 24 and 72 hpi. At both time points, the lowest dose that induced a significant increase in the expression levels of mRNAs (LOEC) for E2 differed among the genes; LOECs were estimated as 10(-11) M for chgHa at 24 hpi, as 10 -9 M for vtgC at 72 hpi, and as 10(-19) M for other mRNAs at both 24 and 72 hpi. Meanwhile, the levels of esrla mRNA exhibited a dose-dependent increase at 24 and 72 hpi, but the LOEC shifted from 10(-9 )M at 24 hpi to 10(-7) M at 72 hpi because of a decrease in mRNA levels at treatment groups exposed to high concentrations of E2. All Esr subtypes transactivated chg, vtg and esrl a promoters in the presence of E2 in vitro. The activation levels indicated that promoter activity of chgHa > vtgAs > chgH5 > chgL > vtgC > esr1a when mediated by Esr1a, chgHO > chgHa > chgHL > vtgAs > vtgC > esr1a by Esr1b, chgHO > chgL > chgHa > vtgAs > vtgC > esr1a by Esr2a, and chgHO > chgHa > vtgAs > chgL > vtgC > esr1a by Esr2b. Collectively, different Esr subtypes were distinctly different in their ability to t

Published
2021

22. Late spring radiolarian fauna in the surface water off Tassha, Aikawa Town, Sado Island, central Japan

Author

Itaki, Takuya, Matsuoka, Atsushi, Yoshida, Kazuhiro, Machidori, Satoru, Shinzawa, Midori, and Todo, Takashi

Subjects
water temperature, Tsushima Warm Current, plankton, Japan Sea, Sado Island, Radiolaria
Abstract

Fifteen radiolarian species were found in a plankton sample collected from surface water shallower than 10 m at the eastern margin of the Japan Sea off Tassha, Aikawa Town, Sado Island, central Japan in late May 2002. The late spring fauna was characterized by Lithomellisa setosa, Tetrapyle octacantha, Stylodictya spp., Spongodiscus spp. and Larcopyle butschlii. It is similar to that reported in late June 2001, but is different from that in early September 2000. Most individuals of warm-water species such as T. octacantha, Didymocyrtis tetrathalamus and Euchitoniafurcata were juveniles.

Published
2003

25. Ovarian yolk formation in fishes: Molecular mechanisms underlying formation of lipid droplets and vitellogenin-derived yolk proteins

Author

Hiramatsu, Naoshi, primary, Todo, Takashi, additional, Sullivan, Craig V., additional, Schilling, Justin, additional, Reading, Benjamin J., additional, Matsubara, Takahiro, additional, Ryu, Yong-Woon, additional, Mizuta, Hiroko, additional, Luo, Wenshu, additional, Nishimiya, Osamu, additional, Wu, Meiqin, additional, Mushirobira, Yuji, additional, Yilmaz, Ozlem, additional, and Hara, Akihiko, additional

Published
2015
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27. Biochemical and Immunochemical Characterization of Two Discrete Vitellogenin Proteins and Their Derived Lipovitellins in the Inshore Hagfish (Eptatretus burgeri)

Author

Nishimiya, Osamu, Kunihiro, Yasuyuki, Hiramatsu, Naoshi, Inagawa, Hiroyuki, Todo, Takashi, Hara, Akihiko, Nishimiya, Osamu, Kunihiro, Yasuyuki, Hiramatsu, Naoshi, Inagawa, Hiroyuki, Todo, Takashi, and Hara, Akihiko

Abstract

Vitellogenesis has been extensively studied in oviparous vertebrates, including teleost fishes, while not much is known with regard to jawless hagfishes, modern representatives of the most primitive vertebrate class. This study aimed to characterize vitellogenin (Vtg) and yolk protein (YP) in the inshore hagfish (Eptatretus burgeri) as an initial step to understand vitellogenesis in this species. A putative Vtg fraction was purified from the serum of female hagfish by combinations of hydroxylapatite and ion-exchange chromatography, followed by gel filtration. The purified fraction appeared to contain two distinct Vtgs (Vtg1 and Vtg2) and exhibited biochemical properties resembling those previously reported for teleost Vtgs; these appeared to be female-specific serum proteins and high-molecular-weight proteins in gel filtration (similar to 505 kDa as the mixture fraction of both Vtgs) and in SDS-PAGE (Vtg1 and Vtg2; similar to 210 kDa and similar to 195 kDa, respectively). A major YP was also purified from hagfish eggs by combinations of hydroxylapatite chromatography and gel filtration; the apparent native mass of the purified YP was unusually large (>669 kDa). The purified YP consisted of four polypeptides in SDS-PAGE; the peptide pattern indicated that it consisted of two lipovitellins (Lv1 and Lv2) giving rise to two sets of heavy chains (similar to 116 kDa and similar to 106 kDa, respectively) and two light chains (similar to 32 kDa and similar to 28 kDa, respectively). Additional immunological analysis, N-terminal amino acid sequencing and cDNA cloning firmly confirmed the precursor-product relationship between hagfish Vtgs and Lvs.

Published
2014

28. Molecular Cloning and Characterization of the Expression Profiles of Vitellogenin Transcripts in the Dojo Loach (Misgurnus anguillicaudatus) in Response to 17 alpha-ethinylestradioland 17 beta-estradiol Administration

Author

Wu, Meiqin, Nishimiya, Osamu, Nakamori, Misato, Soyano, Kiyoshi, Todo, Takashi, Hara, Akihiko, Hiramatsu, Naoshi, Wu, Meiqin, Nishimiya, Osamu, Nakamori, Misato, Soyano, Kiyoshi, Todo, Takashi, Hara, Akihiko, and Hiramatsu, Naoshi

Abstract

The gene, vitellogenin (vtg) was cloned and characterized in the dojo loach (Misgurnus anguillicaudatus), an indigenous freshwater species in East Asia, in order to develop tools for detecting the effects of estrogenic endocrine-disrupting chemicals (EEDCs). Full-length cDNAs encoding seven distinct vtg transcripts (vtg1-7) were obtained. The corresponding deduced amino acid sequences (Vtg1-7) were divided into two types; type I (Vtg1-6; 89-99% identical), which contained both lipovitellin (Lv) and phosvitin (Pv), and type II (Vtg7), which contained Lv alone. Phylogenetic analysis revealed that the type I and type II Vtgs in the loach could be classified as VtgAo1 and VtgC types, respectively. Immuno-biochemical analyses using type-specific Vtg antisera revealed that VtgAo1 proteins appeared to be the major Vtg type in this species. Males were administered (aqueous exposure) either 17 beta-estradiol (E2) or 17 alpha-ethinylestradiol (EE2), the results from which were used to determine that hepatic vtgAo1 expression was estrogen-sensitive. The precise classification of the loach vtg/Vtg products, as well as their induction profiles following the estrogenic stimulation, provide a basis for their use as sensitive biomarkers when EEDC activities are evaluated in the freshwater environments in East Asia.

Published
2014

29. Lrp13 is a novel vertebrate lipoprotein receptor that binds vitellogenins in teleost fishes

Author

Reading, Benjamin J., primary, Hiramatsu, Naoshi, additional, Schilling, Justin, additional, Molloy, Katelyn T., additional, Glassbrook, Norm, additional, Mizuta, Hiroko, additional, Luo, Wenshu, additional, Baltzegar, David A., additional, Williams, Valerie N., additional, Todo, Takashi, additional, Hara, Akihiko, additional, and Sullivan, Craig V., additional

Published
2014
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30. In vitro induction of gonadal sex change in a protogynous fish, three-spotted wrasse (Halichoeres trimaculatus)

Author

Todo, Takashi, Sato, Mana, Ashida, Misa, Yamaguchi, Naohiro, Kobayashi, Yasuhisa, Adachi, Shinji, Yamauchi, Kohei, and Nakamura, Masaru

Subjects
17α-ethynylestradiol, 17α-methyltestosterone, Sex differentiation, Sex reversal, Tilapia, sense organs
Abstract

Recently, we succeeded in inducing in vitro spermatogenesis in a protogynous hermaphrodite fish, threespotted wrasse (Halichoeres trimaculatus), during organ culture of ovary with a serum-supplemented medium. In the pres- ent study, we further optimized and used this culture system to determine effective steroid doses to induce sex change, and to investigate the importance of apoptosis during sex change in vitro. The results show that the restructuring from ovary to testis in the wrasse could be induced in vitro with a serum-free medium. Gonadal sex change can be triggered during basic in vitro culture due to a lack of endogenous factors (especially, estrogens) for female sexuality, and can be accelerated by androgens. Furthermore, oocyte apoptosis may be an important mechanism effecting gonadal sex change.

Published
2008
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31. In vitro induction of oil droplet accumulation into previtellogenic oocytes of Japanese eel, Anguilla japonica

Author

Endo, Taku, Todo, Takashi, Lokman, P. Mark, Ijiri, Shigeho, Adachi, Shinji, and Yamauchi, Kohei

Subjects
endocrine system, technology, industry, and agriculture, lipids (amino acids, peptides, and proteins), eye diseases, Androgen, Eel, Organ culture, VLDL
Abstract

Accumulation of oil droplets in previtellogenic oocytes of Japanese eel, Anguilla japonica, could be induced in vitro. Co-treatment with very low-density lipoprotein (VLDL) and 11-ketotestosterone (11-KT) resulted in significant oil droplet accumulation. It is therefore suggested that lipids in oil droplets originate, at least in part, from VLDL, and that 11-KT plays an important role in their transfer and/or accumulation into oocytes.

Published
2008
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32. A Novel Protein, CHRONO, Functions as a Core Component of the Mammalian Circadian Clock

Author

Goriki, Akihiro, primary, Hatanaka, Fumiyuki, additional, Myung, Jihwan, additional, Kim, Jae Kyoung, additional, Yoritaka, Takashi, additional, Tanoue, Shintaro, additional, Abe, Takaya, additional, Kiyonari, Hiroshi, additional, Fujimoto, Katsumi, additional, Kato, Yukio, additional, Todo, Takashi, additional, Matsubara, Akio, additional, Forger, Daniel, additional, and Takumi, Toru, additional

Published
2014
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35. Molecular cloning and partial characterization of an ovarian receptor with seven ligand binding repeats, an orthologue of low-density lipoprotein receptor, in the cutthroat trout (Oncorhynchus clarki)

Author

Luo, Wenshu, primary, Ito, Yuta, additional, Mizuta, Hiroko, additional, Massaki, Kiyohiro, additional, Hiramatsu, Naoshi, additional, Todo, Takashi, additional, Reading, Benjamin J., additional, Sullivan, Craig V., additional, and Hara, Akihiko, additional

Published
2013
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