东北梅花鹿初级卵母细胞的超微结构

研究东北梅花鹿初级卵母细胞发育的超微结构变化,目的是为探索东北梅花鹿初级卵母细胞的发育规律提供组织学和形态学依据。本研究于2003年和2004年的6月初到8月末取3只、9月中旬到10月初取4只,共计7只健康经产2~3胎的成年东北梅花鹿卵巢;卵巢经2·5%戊二醛固定液固定后,切取约1mm3的卵巢皮质和直径0·5~1·5mm及1·5~3mm的卵泡作为电镜观察用材料;该材料经0·1MpH7·2的PBS漂洗、1%锇酸固定、不同浓度乙醇脱水后,再经Epon812和丙酮等量混合液浸透,最后用Epon812包埋制块,并用半薄切片机切成0·5~2μm半薄切片;再经亚甲基兰-天青Ⅱ染色后,在光镜下进行卵泡分类和卵母细胞定位;将经定位的材料用超薄切片机切成厚度为700~800的切片,经醋酸铀和柠檬酸铅双重染色后,用透射电镜观察、记录并照相。观察时将卵泡依其直径大小、透明带的形成、卵泡腔的出现等分为原始卵泡、初级卵泡、次级卵泡和三级卵泡4类。研究结果表明,在原始卵泡阶段,卵母细胞为较规则的圆形,质膜与卵泡细胞膜紧密相贴,有时形成桥粒,细胞器多分布于近核区,高尔基体不典型,线粒体多为圆形,嵴较少;在次级卵泡阶段,2~4层的卵泡细胞局部开始形成透明带,4层以上时形成薄的透明带,微绒毛斜伸入透明带内,方向不规律;在直径为0·5~1·5mm的三级卵泡阶段,卵母细胞的透明带增厚,各种细胞器在皮质区内数量较多,皮质区内高尔基体的数目增多,粗面内质网明显减少;在直径为1·5~3mm的三级卵泡阶段,卵母细胞的透明带继续加厚,微绒毛缩短变弯,开始从透明带退出,许多皮质颗粒开始排列在卵母细胞膜下。

Ultrastructure of the primary oocyte in Northeast sika deer(Cervus nippon hortulorum)

Seven 4 to 5 years old female Skia deer(Cervus nippon hortulorum) both in their reproductive and non-reproductive season were used to study the ultrastructural changes of the primary oocytes during their development by using transmission electron microscopy. The ovarian tissues were treated according the requirement for the examination via electron microscope. The follicles were divided into 4 groups according to their development. The results showed that at the primordial follicle stage,the oocyte was round and its plasma membrane closely adhered to the follicle cells,most organelles located were near the nucleus, the Golgi complex was not typical, and most mitochondria with fewer cristae were round. At primary and secondary follicle stage, follicles locally formed zona pellucida when they consisted of 2 to 4 layers of follicle cells,irregular microvili on the oocyte were present in the zona pellucida. At teriary follicle stage with a diameter of 0.5 mm to 1.5 mm, the zona pellucida became thick, the number of rough endoplasmic reticulum decreased obviously, and all kinds of organelles and the Golgi complex increased number in the cortex. At the 1.5 mm to 3 mm diameter follicle stage, the zona pellucida kept on increasing in its thickness, the microvili on oocyte became short and curving and started to withdraw from the zona pellucida, and a large number of cortical granules began to laid beneath the plasma membrane of the oocyte.