阳山鸡出生后早期左卵巢组织结构发育的变化

Developmental changes of histological structures in the left ovary of newborn Yangshan chicken

目的:观察阳山鸡卵巢生后早期发育。方法:采用常规组织学方法,比较1~7 d龄阳山鸡左卵巢组织结构的发育变化过程。结果:出生时双侧卵巢已经显示左右明显的不对称,右侧卵巢于5 d龄开始退化,而左侧卵巢持续发育,形状为扁椭圆形,分为2叶;颜色为灰白色。切片观察可见,出生时鸡左侧卵巢实质由皮质、外髓质和内髓质构成。皮质主要由处于减数分裂前期的卵母细胞构成,3 d龄时卵母细胞的染色体进一步凝缩;5 d龄时皮质的卵母细胞全部消失,外髓质已开始有成形的卵泡出现;大约7 d龄时,外髓质的卵泡大而清晰,皮质几乎完全消失,外髓质最终成为真正的皮质。结论:在生后1周内,阳山鸡左卵巢皮质发生明显衰退、崩解和丢失,外髓质最终成为真正的皮质。

Objective:To observe the histological changes of the left ovary just after hatching.Methods:The developmental changes in the histological structures of the left ovary for 1 to 7-day-old Yangshan chicken were observed with histological methods.Results:The macroscopic results showed that just after hatching,both the right and left ovaries exhibited asymmetry and the right started to regress at day 5 old whereas the left continued developing and presented a flat eliptic,bilobated and ashen organ.Microscopical results indicated that the parenchyma of the left ovary constituted the cortex,out medulla and inner medulla.The cortex was mainly made up of oocytes at prophase of meiosis.At day 3,the chromosomes of the oocytes in the cortex were further condensed.But at the day 5,all the oocytes in the cortex were lost and a few primary follicles occurred already in the out medulla.Up to day 7,many primary follicles with perfect profiles were already presented in the out medulla and the cortex had disappeared at all.The out medulla would transfer into the ultimate cortex.Conclusion:In the first week after hatching,the cortex of the left ovary in Yangshan chicken exhibits obvious degeneration,collapse and vagrancy and the out medulla transforms into the eventual cortex.