Molecular Regulation of Gonadotropin Gene Expression in Teleosts

Chong, Kok Leong; Koh, Mingshi; Melamed, Philippa

doi:10.1142/9789812569189_0003

Cited by 5 publications

(1 citation statement)

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“…It has been well established that spermatogenesis is generally controlled by hormonal influences and germ cell-somatic cell interaction in teleosts as well as in other vertebrates (reviewed by Chong et al, 2005;Sherwood & Adams, 2005;Young et al, 2005). Germ cell differentiation synchronously progresses in every cyst under a combined effect of the hormones and signalling molecules from somatic cells.…”

Section: Discussionmentioning

confidence: 99%

Partial formation of sperm dimorphism from spermatocytes of the cottoid fish, Hemilepidotus gilberti in cell culture

Hayakawa

Takayama‐Watanabe

Watanabe

et al. 2007

Zygote

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Polymorphism of sperm is considered to be significant for the reproductive strategy in some animal species. The phenomenon is thought to occur in the species-specific stage of spermatogenesis, but how the identical germ cells are differentiated towards polymorphic sperm remains unknown. We here performed a germ cell culture in the cottoid fish, Hemilepidotus gilberti, whose sperm exhibit dimorphism with fertilizable eusperm and unfertilizable parasperm. In the culture, germ cells, which were obtained with an identical morphology, a spherical shape of 5-7 microm in diameter, differentiated into smaller spherical cells with a single nucleus, a moving flagellum and localized mitochondria. In addition, large retroflex-shaped cells with two elongated nuclei were also observed in the cell culture. Germ cells that had each morphological feature were histologically also observed in some cysts of the spermatogenetic testis, suggesting that the former type of cell corresponded to developing eusperm and the latter corresponded to developing parasperm. When BrdU was incorporated into germ cells in the culture, it was detected in both cells with eusperm-like and those with parasperm-like morphologies. These findings suggest that DNA-duplicating spermatocytes are potent to autonomously progress a part of spermatogenesis to form dimorphic sperm.

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Section: Discussionmentioning

confidence: 99%