性类固醇激素在虾夷扇贝性腺发育周期的分布

Distribution of Sex Steroids in the Gonad of Patinopecten yessoensis During the Reproductive Cycle

性类固醇激素不仅在脊椎动物性别分化、生殖、发育等过程中发挥重要作用,在部分软体动物中也参与生殖调控。本文分析了3种主要性类固醇激素(孕酮、睾酮和雌二醇)在虾夷扇贝性腺发育过程中的变化情况。首先通过组织学方法确定虾夷扇贝性腺4个发育阶段的周年分布:休止期(7—9月)、增殖期(10—12月)、生长期(1—2月)、成熟期(1—6月)。之后,采用酶联免疫吸附实验测定虾夷扇贝性腺各发育阶段中性类固醇激素的含量。结果表明,性腺中激素含量呈现孕酮>雌二醇>睾酮,它们分别约占激素总含量的60%、30%、10%;精巢中3种激素含量均呈显著正相关,但卵巢中仅孕酮和睾酮之间显著相关;研究还发现,虽然3种激素含量在性别、发育阶段之间差异均不显著,但睾酮比例和雌二醇/睾酮在生长期的精巢和卵巢之间差异显著,精巢睾酮比例高于卵巢,而卵巢的雌二醇/睾酮高于精巢。以上结果表明,性类固醇激素很可能参与虾夷扇贝生殖调控,在性腺发育、配子发生过程中发挥重要作用。

Sex steroid hormones play an important role in gender differentiation, reproduction and development in vertebrates. They also participate in reproductive regulations in some molluscs. In this study, we examined the variations of three major sex steroids(progesterone, testosterone and estradiol) during the gonadal development of Patinopecten yessoensis. Firstly, annual distribution of the four developmental stages of Patinopecten yessoensis gonads was determined by histological sections: resting stage(July-September), proliferative stage(October-December), growing stage(January-February) and maturation stage(January-June). Then, levels of the three hormones in the gonads of various developmental stages were detected by enzyme-linked immunosorbent assay(ELISA). Results showed that the level of progesterone is highest in scallop gonads, followed by estradiol and testosterone, accounting for about 60%, 30% and 10% of the total content of the sex steroids, respectively. In testis, correlations between the three hormones are significantly positive, but in ovary, only the correlation between progesterone and testosterone is significant. Although levels of the three hormones do not vary significantly between sex or gonadal developmental stages, there are significant differences in testosterone% and estradiol/testosterone between testis and ovary at growing stage, with testosterone% being higher in testis, and estradiol/testosterone being higher in ovary. These results suggest that sex steroids may participate in scallop reproductive regulation, including gonadal development and gametogenesis.