Morphology, endocrinology, and environmental modulation of gonadal sex differentiation in teleost fishes |
| |
Authors: | Carlos Augusto Strüssmann and Masaru Nakamura |
| |
Institution: | (1) Department of Aquatic Biosciences, Tokyo University of Fisheries, Konan 4-5-7, Minato, Tokyo, 108-8477, Japan (Phone/Fax;(2) Tropical Biosphere Research Center, University of the Ryukyus, Sesoko Station. 3422 Sesoko, Motobu, Okinawa 905-0227, Japan |
| |
Abstract: | Successful reproduction by an adult depends on the normal ontogenesis of the gonads, a complex process of cellular and histological
differentiation that starts early in life. This process is theoretically predetermined by genetic factors and includes sensitisation
of the bipotential gonads to endogenous endocrine factors prior to, during and even after commitment to maleness or femaleness.
However, young fish are relatively vulnerable to a host of environmental (physical and chemical) factors that can affect this
endogenous endocrine axis, disturbing or even overriding the putative developmental pathway. This sexually lability can be
exploited to our advantage for the production of monosex fish populations of the most valuable sex for food production or
aquarium fish trade. On the other hand, it represents also a potential path for undesirable influences from endocrine-disrupting
chemicals and climatic factors, particularly environmental temperature. This paper provides a detailed account of the early
histological process of gonadal sex differentiation, with special reference to gonochoristic species, and reviews the criteria
employed to positively identify ovarian and testicular differentiation. It also reviews the development of endocrine competence
and sensitivity of the differentiating gonads to exogenous influences in the context of the relative stability of genotypic
sex determination in various fish species. Sex differentiation in some species seems to be under strong genetic control and
may not require endogenous sex steroid production. Conversely, reliance on endogenous sex steroids for gonadal differentiation
is observed in other species and this phenomenon is apparently associated with a higher incidence of environment (mainly temperature)-labile
sex differentiation.
This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
Keywords: | environment fish sex determination sex differentiation steroidogenesis |
本文献已被 SpringerLink 等数据库收录! |
|