树鼩(Tupaia belangeri chinensis)卵巢的显微结构及不同季节的卵巢活动

本文报道不同季节的野外成体树鼩卵巢结构的观察和卵泡发育测定的结果。树鼩卵巢的间质腺组织稀少,但普遍有“睾丸索”型的髓质索结构。卵泡发育过程类似于大多数哺乳类和灵长类。近成熟卵泡的腔极大,内膜较窄并有插入的膜腺细胞层。孕期成熟黄体较大,中间有小腔,多角形的黄体细胞具圆形的核和富含脂滴的胞质。带退化透明带残体的付黄林结构偶尔可见,有的与孕期黄体同时出现。次级卵泡和中等囊状卵泡的发育未见有明显的季节性差别。但是,具生长活性的大囊状卵泡和近成熟卵泡的发育,在1、4月份更为明显,为卵泡前期和卵泡期的卵巢周期形态者较多。孕期黄体和付黄体结构见于7月份。10月份未见孕期卵巢结构,多数卵巢缺乏生长活性的大囊状卵泡的发育。这些结果表明,树鼩的卵巢活动同睾丸的精子发生一样,有季节性变化。

MICROSCOPIC STRUCTURE OF OVARY AND OVARIAN ACTIVITY OF DIFFERENT SEASONS IN TREE SHREW (TUPAIA BELANGERI CHINENSIS)

Micro.scopic structure of ovary and follicular development in wild adult tree shrews from Kunming, Yunnan were observed at different seasons. Interstitial gland tissues are rare, but medullar cords of "testis cord" type are com-monly present in ovaries of this species. Follicle development appears to be similar to typical pattern of mammals. Nearly ripe follicles have rather larger follicuiar anlra and thinner theca interim interrupting zone oi thccal gland cells. The mature corpus luteurn in pregnancy cycle is considerably big and there is an extremely small connective tissue center. Large polyhedral luteal. cells with round nuclei accumulate abundant lipid droplets in cytoplasm. Accessory corpus luteum (ACL) structure with degenerative zona pellucida is seen in some animals, and some of ACL are present with gravid corpus luicum. Development of secondary follicles and medium-sized vesicular follicles seem to be no seasonal differences, but development of larger vesicular follicles and nearly ripe follieles occurs obviously in Jan and Apr. It is possible that there are more ovarian cycles of follicuiar propliase and follicuiar phase in these groups. Corpus luteum of pregnancy cycle and ACL are seen in Jul. No structure of pregnancy cyclic ovary is discovered in Oct, and there are more inactive ovaries which have almost no development of actively growing larger vesicular follicles in this group. These results suggest that seasonal changes in ovarian activity appear in this species. The earliest onset of estrus may begin in Jan. It is fully non-breeding season in Oct. The seasonal disruption of ovarian cycle may be controlled by some of the environmental and endocrine factors.