【摘要】 电镜观察猪卵泡中后期卵母细胞(OC)超微结构,有两种变化,一是进行性变化:细胞质内含大量脂滴(Li)。线粒体(Mi)和内质网(ER)囊泡集群分布于近皮质区。随OC的增大,二者有分散于全细胞的倾向;皮质颗粒(CGs)的直径、分布密度都增加但膜距减少;微绒毛(MV)数量、直径和长度逐渐变少、大、短。颗粒细胞(GC)逐渐老化。二是闭锁变化:核膜皱折,染色质浓缩;Mi互相融合并出现空泡;ER囊扩大融合;Li减少;卵膜皱缩与透明带间出现大的裂隙;GC质中出现空泡,核膜破裂;GC数量减少,严重者则完全消失。统计分析表明,卵泡直径5mm时其闭锁率最高。更多还原

【Abstract】 Under the electron microscope, there were two kinds of ultrastructr-ural changes in the oocytes in middle and late follicles of sows.The, first was a progressive change:There were agreat many lipid drops ( LD ) in the cytoplasm and the mitochondria ( Mi ) and endoplasmic reticulum ( ER ) clustered near the cortical region. As the oocytes ( OC ) grew, cortical granules ( CG ) increased in diameter and in dispersing density, but their distance to the oo-lemma was, shortened. The microvilli ( MV ) of the OC gradually decreased in number, increased in diameter and shortened in length.Granular cells ( GC ) aged gradually.The second was an atretic change.The nuclear envelope wrinkled, the chromatin condensated and the Mi fused each other, and some vacuoles appeared in them. ER vesicles enlarged and fused with one another.LP reduced in number.The oolem-ma had wrinkled so much that some large crevices appeared between the zona pellcida and the oolemma. Some vacuoles appeared in the cytoplasm of the GC and their nuclear envelope had broken.The GC number decreared and in some extreme case, they were totally absent.Statistical analysis showed that the rate of follicular atresia was the highest when the follicular diameter was 5mm in length.更多还原