中华鳖卵巢的发育

Ovarian Development of Trionyx sinensis

取人工孵化雌性稚鳖和1龄、2龄、3龄、4龄雌性鳖各4只解剖，观察其卵巢的形态学特征，做卵巢组织切片分析其发育特征。结果表明：稚鳖的卵巢发育至卵原细胞期，卵巢内有大量的通过有丝分裂形成的卵原细胞；1龄鳖的卵巢发育至初级卵泡期，卵原细胞的周围包被滤泡细胞，内有空泡，卵核被挤压至细胞边缘；2龄、3龄鳖的卵巢处于生长卵泡期，卵核重返细胞中央，核仁多个，出现灯刷染色体，卵黄自卵周开始沉积并逐渐向中央发展。3龄末的卵巢内可见到成熟卵泡，卵径达2．00～7．57mm，卵巢切片可观察到卵原细胞、初级卵泡、生长卵泡，卵核偏至动物极；4龄鳖的卵巢发育至成熟卵泡期，卵核定位于动物极，卵径达6．44～14．40mm。

Four artificial-hatched juvenile and one-, two-, three- or four-year-old female Chinese soft- shelled turtles （T. sinensis） each were used in this study for histological observation of their ovaries. The ovary of the juvenile T. sinensis was found to have develop to the oogonium phase, many oogonia developed by mitosis were observed in it. The ovary of one-year-old T. sinensis was at the primary follicular phase, the oogonia were surrounded by follicles, and there were vacuoles in them. The ovokaryon was extruded to the cellular margin. The ovaries of two-and three-year-old T. sinensis were found to be at the follicular phase, and the ovokaryon came back to the cellular center. A few nucleoli and lampbrush chromosomes were observed. The yolk began accumulating from the surroundings of the ovum and developed to the center gradually. Mature ova could be observed in the ovary of three-year-old T. sinensis with an ovular diameter of 2.00～7.57 mm. Oogonium, primary oocyte and growing oocyte were found in the histological observation of the ovary with the ovokaryon at the animal polar. The mature follicular phase was found in the ovary of four-year-old T. sinensis. The ovokaryon was at the animal polar and the ovular diameter was 6.44～14.40 mm. Their morphological traits were also studied.