中文摘要：

母猪怀孕后33-61d期间，是胎猪卵母细胞发生的关键阶段。为掌握这一时期卵巢上组织细胞的发育变化，试验采集妊娠33、40、46、54、61d的雌性胎猪卵巢进行苏木精-伊红染色。结果表明，妊娠33d胎猪卵巢表面上皮由1-2层细胞构成，实质见到卵原细胞和髓质索结构；妊娠40d时出现卵原细胞共质体结构和前细线期卵母细胞，髓质索状结构断裂；妊娠46d共质体样结构增多，卵母细胞进入前细线期和细线期。髓质索断裂成片段；妊娠54d时表面上皮由单层细胞构成，卵巢皮、髓可分，皮质中层见到合胞体样卵母细胞群，髓质相邻的皮质深层有一些原始卵泡正在形成；妊娠61d胎猪卵巢皮、髓界限清晰，皮质中层是大量合胞体样卵母细胞群，皮质深层出现了较多的原始卵泡，髓质中卵泡结构退化，卵母细胞发生核固缩。

英文摘要：

From 33 to 61 day during gestation is critical stage of oogenesis for fetal pigs. To elucidate the histological change of ovaries in fetal pig, ovaries of 33, 40, 46, 54, 61 day-old fetal pigs were collected and H-E stained. The results showed that oogonia and medullary cords could be seen in 33 day-old fetal ovaries, which were coated by one or two layers of coelomic epithelial. Synpliasma-like cells and oocytes at preleptotene or leptotene occurred in 40 d fetal ovaries. Synpliasma-like cells increased and oocytes entered preleptotene or leptotene in 46 d fetal ovaries, when medullary cords separate into fragments. Superficial epithelium in 54 d fetal ovaries was made of one layer cells and boundary between cortex and medulla was differentiable. Syncytium- like cell groups appeared in middle cortex and primordial follicles appeared in deep cortex. The cortex and medulla in 61 d fetal ovaries was distinguished. The syncytium-like cell groups occurred in middle cortex and primordial follicles occurred in deep cortex. In medulla, however, follicles degenerated and oocytes had nucleus pyknosis.