Hourigan T F, Nakamura M, Nagahama Y, Yamauchi K, Grau E G
Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki, Japan.
Gen Comp Endocrinol. 1991 Aug;83(2):193-217. doi: 10.1016/0016-6480(91)90023-y.
Species with multiple male reproductive phenotypes may serve as model systems to study the relationship between form and function in reproduction. Large and small males of the protogynous wrasse, Thalassoma duperrey differ in reproductive behavior, gonad morphology, and gonadal steroid production. Initial-phase (IP) males are small males that spawn in groups. They have large testes with high sperm production. Terminal-phase (TP) males are large, defend temporary spawning territories, and spawn individually with females. TP males are derived from either IP males or from sex-changed females. Regardless of origin, TP males have much smaller testes than do IP males, but steroid-producing Leydig cells in the gonads of TP males appear more numerous and better developed. Testes of TP males produce more testosterone (T) and especially 11-ketotestosterone (11-KT) in vitro than do testes of IP males, and the production is more responsive to salmon gonadotropin. 11-KT was the major metabolite produced by incubating the gonads of TP males with 14C-labeled steroid precursors. In vitro 11-KT production was correlated with plasma levels of 11-KT in TP males and these levels were significantly higher than those of IP males. The in vitro conversion of 17 alpha-hydroxyprogesterone to 17 alpha, 20 beta-progestogen (17 alpha, 20 beta-P) for both types of males was similar, and was highest in winter when spawning occurred every day. Basal production of 17 alpha, 20 beta-P was similar in IP and TP male testes, and was enhanced by gonadotropin. The enzyme 20 beta-hydroxysteroid dehydrogenase, responsible for the conversion of 17 alpha-hydroxyprogesterone to 17 alpha, 20 beta-P resided in the sperm. These results indicate a function of 17 alpha, 20 beta-P in male reproductive function, probably spermiation, and a relationship of Leydig cell development and high levels of 11-KT production to the terminal male phenotype, perhaps reproductive or aggressive behavior, rather than to male gametogenesis per se.
具有多种雄性生殖表型的物种可作为研究生殖中形态与功能关系的模型系统。雌性先熟的杜氏海猪鱼的大小雄性在生殖行为、性腺形态和性腺类固醇生成方面存在差异。初始阶段（IP）雄性是成群产卵的小雄性。它们有大的睾丸，精子产量高。终末阶段（TP）雄性体型大，保卫临时产卵领地，并与雌鱼单独产卵。TP雄性要么来自IP雄性，要么来自性逆转的雌性。无论起源如何，TP雄性的睾丸都比IP雄性小得多，但TP雄性性腺中产生类固醇的莱迪希细胞似乎更多且发育更好。TP雄性的睾丸在体外产生的睾酮（T）尤其是11 - 酮睾酮（11 - KT）比IP雄性的睾丸多，并且这种产生对鲑鱼促性腺激素更敏感。11 - KT是用14C标记的类固醇前体孵育TP雄性性腺产生的主要代谢产物。体外11 - KT的产生与TP雄性血浆中11 - KT水平相关，且这些水平显著高于IP雄性。两种类型雄性的17α - 羟基孕酮向17α, 20β - 孕烯醇酮（17α, 20β - P）的体外转化相似，且在每天产卵的冬季最高。IP和TP雄性睾丸中17α, 20β - P的基础产量相似，并被促性腺激素增强。负责将17α - 羟基孕酮转化为17α, 20β - P的20β - 羟基类固醇脱氢酶存在于精子中。这些结果表明17α, 20β - P在雄性生殖功能中发挥作用，可能与精子排放有关，并且莱迪希细胞发育和高水平11 - KT产生与终末雄性表型相关，可能与生殖或攻击行为有关，而非与雄性配子发生本身有关。
