【作者】 雷忻；

【导师】 张育辉；

【作者基本信息】 陕西师范大学 ， 动物学， 2003， 硕士

【摘要】 两栖动物卵泡的发育是一个受多种因素调控的极为复杂的过程，性类固醇激素及其受体、原癌基因在这一过程中起着重要的调控作用。性类固醇激素及其受体、原癌基因在卵泡发育周期中的作用、以及三者之间相互关系的研究，在卵子发育机制的研究中具有重要的意义。本研究以隆肛蛙和山溪鲵为材料，运用组织学方法，对其卵泡发育周期进行分析；并首次运用免疫细胞化学方法，对两种两栖动物类固醇激素雌二醇、孕酮和睾酮及其受体、原癌基因c-myc、c-fos在卵泡发育中的调控作用，以及激素、受体、原癌基因三者之间的关系进行了初步研究，结果如下： 1．隆肛蛙的卵巢存在着显著的个体差异，就每个雌体而言，一年只排一次卵，排卵时间很短。但就秦岭山区的隆肛蛙种群而言，排卵期为每年的4-6月。10月下旬至翌年3月隆肛蛙卵巢处于休眠期。 2．山溪鲵卵泡发育个体差异较小，为一年一次排卵，时间在每年3-4月，4-10月为卵泡发育阶段，11月下旬至翌年3月为冬眠期。 3．隆肛蛙和山溪鲵卵泡闭锁的意义之一可能是控制卵母细胞的数量，以有限的营养物质保证一定数量卵母细胞成熟。闭锁黄体主要发生在Ⅲ、Ⅳ期卵泡中，可能具有分泌类固醇激素的功能。 4．隆肛蛙卵巢滤泡细胞是合成与分泌雌二醇和孕酮的场所，膜细胞是合成与分泌睾酮的场所，两种类型细胞相互协作，共同完成其分泌活动。从形态学和免疫细胞化学的角度证明，用两类细胞模型解释卵巢类固醇激素的合成与分泌是合理的。 5．山溪鲵三种卵巢类固醇激素可能都是在滤泡细胞中合成，膜细胞不具有内分泌功能，说明卵巢分泌细胞并未发生功能上的分化，表现出有尾两栖动物生殖功能的原始性。 6．雌二醇在隆肛蛙和山溪鲵的卵黄合成和积累中起重要作用，孕酮与睾酮在隆肛蛙卵母细胞成熟中、孕酮在山溪鲵卵母细胞成熟中起着重要的调节作用。说明，在卵母细胞发育中，有尾两栖类和无尾两栖类性类固醇激素的作用有一些差异。三种类固醇激素存在相互转化的关系，睾酮可能在雌二醇和孕酮的转化中起着底物的作用，这种转化与某种芳香化酶的活性有关。 7．在隆肛蛙和山溪鲸滤泡细胞中，类固醇激素受体可能在类固醇激素的合成和分泌中起一定的调控作用，并且，在滤泡细胞的生长发育中也有重要的作用。类固醇激素受体在卵母细胞中可能通过两种途径发挥作用，一种是存在于胞质中，作为信号转导因子的非基因组调控机制；另一种是存在于核中，作为核转录活性因于，改变基因转录活动的基因组调控机制。这两种作用方式可能同时存在，相互协作，共同调控卵母细胞的发育和成熟。 8．在隆肛蛙和山溪鲸卵母细胞发育早期，C－p可能起一定的调节作用，而CghS则可能在发育中、后期起作用。在整个发育过程中，两种原癌基因与卵巢类固醇激素有一定的相关性。此外，两种原癌基因还可能在滤泡细胞中发挥作用。 9．隆肛蛙和山溪鳃闭锁黄体具有内分泌功能，可以协助滤泡细胞合成雌二醇，以保证卵黄的合成。闭锁黄体中的雌激素受体可能在其内分泌功能中起着重要的调控作用，维持适量雌二醇的分泌，以保证卵母细胞的正常发育。更多还原

【Abstract】 The development of amphibian oocyte is extensively regulated by various factors. Sex steroids and their receptors, proto-oncogenes play key roles in the regulations. Studies on the regulations of steroids, receptors and proto-oncogenes during the follicle development, and studies on these multual relations, have great significance in the study on the mechanism of the oocyte development. Firstly, using histological method,the thesis studied the peroid of follicle development of the Rana quadranus and the Batrachuperus tibetanus. Secondly, the studies of regulations of estradiol, progesterone, testosterone, and their receptors, c-myc, c-fos during follicle development of this two amphibians were carried out by using immunocytochemical method. The results are as follows.1. The obvious individual difference exists in the ovary of the Rana quadranus. Each female only ovulates once every year and the ovulation lasts a very short period of time. However, for the community that lives in Qinling mountain area, the spawning period start in Apr, and end in Jun.2. There is little difference among the individual of the Batrachuperus tibetanus. Each female only ovulates once every year, while the whole community’s spawning period lasts from Mar to Apr.3. One of significance of the follicle atresia of the Rana quadranus and the Batrachuperus tibetanus is that it makes the amount of oocyte under control and it guarantees sufficient oocytes maturation under the condition of limited nutrition. The corpora atrestics which are mainly formed at III and IV stages of follicle development are probably have the ability to secrete steroids.4. For the Rana quadranus, the follicle cells are the main sites for estradiol(E2) and progesterone(P), whereas the thecal cells are the primary source for testosterone(T). They cooperate with each other and accomplish the secretion. From the point of morphology and immunocytochemistry, it is proved that it is reasonable to analysis the follicular steroidogenesis of the Rana quadranus by using the two-cell type model.5. For the Batrachuperus tibetanus, the follicle cells are the main sites for e2, P and T, but the thecal cells are not shown to product steroid. So we propose that the steroidogenic cells in the ovary do not differentiate in their funtions, which shows primitive characteristic in reproduction of urodeles.6. E2 plays a key role in the synthesis and accumulation of yolk protein of the Rana quadranus and the Batrachuperus tibetanus. P and T regulate oocyte maturation of the Rana quadranus, but only P in the regulation of the Batrachuperus tibetanus. That shows there are some difference in the steroid regulation between the anuras and the urodeles. Among three of the steroid, one can convert to the other, and some enzyme activity is concerned with the conversion.7. For the Rana quadranus and the Batrachuperus tibetanus, the steroid receptors play key roles in the synthesis and secretion of the steroids and during the development of the follicle cell. The receptors can function in two ways. One is as signal transducers outside of the nucleus, named nongenomic action. The other is as transcription activators in the nucleus, named genomic action. The two ways may coexist, cooperate and coregulate in the development and maturation of oocyte.8. C-myc maybe plays a role at the early stage of oocyte development of the Rana quadranus and the Batrachuperus tibetanus, and c-fos at the medium and later stages. Two of the protogenes have some correlation with the three steroids during the oocyte development.9. The corpora atrestic of the Rana quadranus and the Batrachuperus tibetanus are shown to produce E2 to stimulate the synthesis of yolk protein. Estrogen receptor and progestogen receptor in the corpora atrestic regulate the endocrine function of ovary to maintain proper estradiol secretion.更多还原