Hormonal induction of all stages of spermatogenesis in vitro in the male Japanese eel (Anguilla japonica).
- T. Miura, K. Yamauchi, H. Takahashi, Y. Nagahama
- Biology, MedicineProceedings of the National Academy of Sciences…
- 1 July 1991
Results suggest the following sequence for the hormonal induction of spermatogenesis in eel testes; gonadotropin stimulates the Leydig cells to produce 11-ketotestosterone, which activates the Sertoli cells leading to the completion of sPermatogenesis.
Spermatogenesis-preventing substance in Japanese eel.
- T. Miura, C. Miura, Y. Konda, K. Yamauchi
- Biology, MedicineDevelopment
- 1 June 2002
It is concluded that eSRS21 prevents the initiation of spermatogenesis and, therefore, suppression of eS RS21 expression is necessary to initiate sperMatogenesis.
Japanese Eel Follicle-Stimulating Hormone (Fsh) and Luteinizing Hormone (Lh): Production of Biologically Active Recombinant Fsh and Lh by Drosophila S2 Cells and Their Differential Actions on the…
- Y. Kazeto, M. Kohara, K. Yamauchi
- BiologyBiology of Reproduction
- 1 November 2008
The data strongly suggest that Fsh and Lh differentially play important roles in the reproductive physiology of the Japanese eel, which is probably due to the qualitative nature of glycosylation in S2 cells, which resulted in degradation of the recombinant protein in vivo.
Ovarian development and serum sex steroid and vitellogenin profiles in the female cultured sturgeon hybrid, the bester
- B. M. Amiri, M. Maebayashi, A. Hara, S. Adachi, K. Yamauchi
- Biology
- 1 June 1996
The results indicate that the time appropriate for induction of artificial reproduction would be from October–November to April–May when the oocytes are in the late Stages of the development.
Identification of the salmon somatolactin receptor, a new member of the cytokine receptor family.
- H. Fukada, Y. Ozaki, W. Dickhoff
- BiologyEndocrinology
- 1 May 2005
Somatolactin (SL) is a pituitary hormone of the GH/prolactin (PRL) family that so far has been found only in fish. Compared with GH and PRL, the primary structure of SL is highly conserved among…
Estradiol-17beta stimulates the renewal of spermatogonial stem cells in males.
- T. Miura, C. Miura, T. Ohta, M. R. Nader, T. Todo, K. Yamauchi
- Biology, MedicineBiochemical and Biophysical Research…
- 14 October 1999
In vitro, 10 pg/ml of E(2) was sufficient to induce spermatogonial stem cell division in cultured testicular tissue, therefore confirming the in vivo observations, and clearly show that estrogen is an indispensable "male hormone" in the early sperMatogenetic cycle.
Histological and ultrastructural evidence for the role of gonadal steroid hormones in sex change in the protogynous wrasse Thalassoma duperrey
- Masaru Nakamura, T. Hourigan, K. Yamauchi, Y. Nagahama, E. Grau
- Biology, MedicineEnvironmental Biology of Fishes
- 1 February 1989
The process of sex change from ovary to testis was divided into six stages on the basis of changes in the structure of the germinal and somatic elements, and sex change to male was considered complete with the beginning of active spermatogenesis and spermiation.
The role of hormones in the acquisition of sperm motility in salmonid fish.
- T. Miura, K. Yamauchi, H. Takahashi, Y. Nagahama
- Biology, Environmental ScienceThe Journal of experimental zoology
- 1 March 1992
Gonadotropin-induced testicular production of 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one, the oocyte maturation-inducing hormone of salmonid fish, is responsible for the acquisition of sperm motility but neither testosterone (T) nor 11-ketotestosterone (11-KT), the two major androgens in teleost fish, were effective.
INVOLVEMENT OF STEROID HORMONES IN GONADOTROPIN-INDUCED TESTICULAR MATURATION IN MALE JAPANESE EEL (ANGUILLA JAPONICA)
- T. Miura, K. Yamauchi, Hiroya Takahashi, Y. Nagahama
- Biology, Medicine
- 1 August 1991
It is concluded that incomplete testicular and sperm maturation by HCG injections is due in part to the failure of the testis to produce l7cx,20[>’-DP in response to HCG stimula-tion.
Testicular development and serum sex steroid profiles during the annual sexual cycle of the male sturgeon hybrid, the bester
- B. M. Amiri, M. Maebayashi, S. Adachi, K. Yamauchi
- Biology
- 1 June 1996
It is suggested that the time appropriate for induction of final maturation would be from November–December to April when the testes are in the late stage of development.
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