东北细毛羊胎羊卵巢卵泡超微结构研究

为给胚胎工程研究提供基础材料,应用电子显微镜对东北细毛羊不同胎龄胎羊卵巢卵泡的超微结构进行了观察研究,结果表明:1)7周龄胎儿卵巢形成了原始卵泡雏形,10周龄才形成结构较完整的原始卵泡。2)卵母细胞呈圆形或椭圆形。卵母细胞膜双层不规则;核仁呈网状,单核仁或双核仁;核大多位于卵母细胞的边缘;并发现由双核构成的卵母细胞和胞质中形成不含细胞器的“透明区”;在10周胎龄卵巢,发现有1条线正将1个卵母细胞一分为二。早期线粒体多数圆形,但发现了1个线状的线粒体。随着卵母细胞发育,除圆形以外,还出现了类似菱形、不规则型、幼稚型的线粒体。单个粗面内质网可见,但高尔基体却很少见到。12周龄原始卵泡形成类似“透明带”物质。3)卵泡细胞核多数不规则,个别呈扁长形或纺锤形;卵泡细胞环绕于卵母细胞周围,早期数量少,随着卵泡发育逐渐增多。4)东北细毛羊胚胎卵巢卵母细胞发育的各阶段都有一定数量卵母细胞发生退行性变化———闭锁。

Study on ultrastructure of Northeast China fine-fleece sheep fetal follicles

Different gestational age fetal follicles from Northeast China Fine-fleece sheep were histologically studied with electronic microscope,The results showed that:(I) The formation of primordial follicles initiated in the 7th week,the intact structure was formed in the 10th week;(II) Oocytes were round or oval-shaped,pericellular membrane in oocytes was irregular double-deck;nucleus were in the margin of oocytes with single or double nuclei reticularis;transparency area without organelle was found in double nuclei oocytes;a line divied oocytes into two parts in 10-week.Most mitochondria were round,some diamond,irregular and juvenile ones could be found with development of oocytes.Single rough surfaced endoplasmic reticulum could be found,but Golgi complex was rare.Zona pellucida-like structure was found in 12-week.(III) Most nucleus in follicle cells were irregular,some were prolated or fusiform;oocytes were surrounded by follicle cells whose number were gradually increasing.(IV) A certain number of oocytes degenerated in each stage of development.