Title: | Induction of male-type gonadotropin secretion by implantation of 11-ketotestosterone in female goldfish |
Author(s): | Kobayashi M; Furukawa K; Kim MH; Aida K; |
Address: | "Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, 113, Japan" |
ISSN/ISBN: | 0016-6480 (Print) 0016-6480 (Linking) |
Abstract: | "In goldfish, plasma gonadotropin levels increase during spawning in both males and females (GTH surge). A female-typical GTH surge induces ovulation (ovulatory surge), and a male-typical surge triggers milt production in response to sex pheromones released from ovulatory females. This study examined whether the male-typical GTH surge occurs in adult females that are implanted with 11-ketotestosterone (KT), which induces male-typical sexual behavior in adult female goldfish. When KT-implanted females were exposed to ovulatory females, a GTH surge occurred without ovulation. No GTH surge was observed when KT-females were exposed to nonovulatory females. The GTH secretion in KT-females was further characterized by exposure to 17alpha,20beta-dihydroxy-4-pregnen-3-one (17,20-P), a female sex pheromone that induces the GTH surge in males. Exposure to waterborne 17,20-P caused an elevation of GTH levels in KT-females as well as in males. The elevation of GTH levels induced by 17,20-P exposure was abolished when the KT-females were rendered anosmic. Unlike the female-typical ovulatory GTH surge that occurs in synchrony with photoperiod and peaks in the dark phase of the day, the 17,20-P-induced surge did not show a peak in the dark phase. These results indicate that the GTH surge in KT-females is a male-typical surge. Together with a previous study showing KT-induced behavioral masculinization (N. E. Stacey and M. Kobayashi, 1996, Horm. Behav. 30, 434-445), this adult gonochoristic species was shown to possess sexual plasticity of brain function in behavior and GTH secretion in response to sex steroid" |
Keywords: | "Animals Female Goldfish/*physiology Gonadotropins, Pituitary/*blood Hydroxyprogesterones/pharmacology Male Ovulation/physiology Photoperiod Sex Attractants/pharmacology Sexual Behavior, Animal/*drug effects/physiology Testosterone/*analogs & derivatives/p;" |
Notes: | "MedlineKobayashi, M Furukawa, K Kim, M H Aida, K eng Research Support, Non-U.S. Gov't 1998/01/10 Gen Comp Endocrinol. 1997 Dec; 108(3):434-45. doi: 10.1006/gcen.1997.6993" |