Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Youichi Hayakawa"'
Publikováno v:
Fisheries Science. 87:93-104
Estrogenic endocrine-disrupting chemicals are an increasing social concern, as they can reduce the reproductive activity of wildlife. The present study aimed to clarify the long-term effects of estradiol-17β (E2) on male reproductive activity in gol
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9aac85f3d5627486877384e2cb570287
https://doi.org/10.1007/s12562-020-01487-1
https://doi.org/10.1007/s12562-020-01487-1
Autor:
Youichi Hayakawa, Makito Kobayashi
Publikováno v:
Zoological Science. 29:807-814
The asymmetrical and latitudinal formation of the gonads during early development in the dwarf gourami Colisa lalia was histologically observed using fish reared in laboratory. Hatching larvae obtained 33 hours after spawning possessed primordial ger
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e51d5fba018a20d06b4e1df6f716391a
https://doi.org/10.2108/zsj.29.807
https://doi.org/10.2108/zsj.29.807
Autor:
Makito Kobayashi, Youichi Hayakawa
Publikováno v:
Zoological Science. 29:141-146
We examined the importance of establishment and maintenance of territory on reproductive activity in the male dwarf gourami, Colisa lalia. After three males had been forced to fight for territory (five sets) for three weeks, social status was divided
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bad370afc9106518942b12ba0cae6011
https://doi.org/10.2108/zsj.29.141
https://doi.org/10.2108/zsj.29.141
Autor:
Youichi Hayakawa, Orio Yamamura, Masakatsu Fujinoki, Akihiko Watanabe, Yuni Nakauchi, Makito Kobayashi
Publikováno v:
Zoological Science. 28:438-443
The dimorphic sperm of Hemilepidotus gilberti, i.e., haploid eusperm and diploid parasperm, have different morphologies corresponding to their own roles in fertilization. To estimate how these specific sperm morphologies were established, we focused
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fc9404cd860455faa8562f803a39351a
https://doi.org/10.2108/zsj.28.438
https://doi.org/10.2108/zsj.28.438
Publikováno v:
Ichthyological Research. 58:109-125
Testicular structure of 9 species and sperm head morphology of 19 species of Cottidae were observed in order to clarify relationships between morphological characteristics of the male reproductive organ and reproductive mode (copulation or non-copula
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c929aa04e79b8ae28a52bfaafe1c3098
https://doi.org/10.1007/s10228-010-0196-9
https://doi.org/10.1007/s10228-010-0196-9
Autor:
Makito Kobayashi, Youichi Hayakawa
Publikováno v:
Ichthyological Research. 57:40-48
During the course of spawning, the male dwarf gourami Colisa lalia exhibits a clasping behavior where the male bends his body around the female under the floating bubble nest. In this study, in order to investigate the role of this clasping behavior,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::6d39427b4fce1f5c78d57ce80d7658ed
https://doi.org/10.1007/s10228-009-0121-2
https://doi.org/10.1007/s10228-009-0121-2
Publikováno v:
Ichthyological Research. 57:62-70
Annual changes in testicular development and occurrence of parasperm were investigated using 2-year-old male fourspine sculpins Cottus kazika, based on the histological observation of testes. The male reproductive organ of fourspine sculpins comprise
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5090bb9e1fc381a1fdfa2df1d367faa4
https://doi.org/10.1007/s10228-009-0123-0
https://doi.org/10.1007/s10228-009-0123-0
Publikováno v:
Fisheries Science. 75:137-144
We previously demonstrated the biological activities of single-chain recombinant gonadotropins (scGTHs) of goldfish Carrassius auratus follicle-stimulating hormone (scFSH) and luteinizing hormone (scLH), produced by a baculovirus–silkworm larvae sy
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::84c018376c0fecf6cfed088243fa7e77
https://doi.org/10.1007/s12562-008-0007-7
https://doi.org/10.1007/s12562-008-0007-7
Autor:
Akira Banba, Youichi Hayakawa, Tetsuro Morita, Wataru Kitamura, Makito Kobayashi, Hidekazu Nagaya, Young Chang Sohn, Shinji Kanda, Goro Yoshizaki, Komei Hotta
Publikováno v:
Aquaculture. 274:408-415
Recombinant gonadotropins (GTHs), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) of goldfish Carassius auratus were previously produced by baculovirus in silkworm larvae Bombyx mori. These GTHs are heterodimeric hormones consisting o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5299850b8b753a7719b5f06f087701d4
https://doi.org/10.1016/j.aquaculture.2007.12.002
https://doi.org/10.1016/j.aquaculture.2007.12.002
Autor:
Hiroyuki Munehara, Youichi Hayakawa
Publikováno v:
Journal of Fish Biology. 64:1530-1539
Euspermatozoa and paraspermatozoa of a copulatory (internal insemination with external sperm transfer) cottoid fish Blepsias cirrhosus were observed ultrastructurally. Euspermatozoa of B. cirrhosus consisted of an acrosome-less, thin, disk-like sperm
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4b2c4d4aa9954aa8cbe80d252c0febf4
https://doi.org/10.1111/j.0022-1112.2004.00407.x
https://doi.org/10.1111/j.0022-1112.2004.00407.x