棕色田鼠XO雌体的减数分裂  

Meiosis of XO Females in the mandarin vole Microtus mandarinus

作　　者：朱必才[1] 张子峰[1] 张永[1] 高俊芳[1] 董玉玮[1] 侯进慧[1] 

机构地区：[1]徐州师范大学生物系,徐州221116

出　　处：《动物学报》2004年第1期68-74,共7页ACTA ZOOLOGICA SINICA

基　　金：国家自然科学基金资助 ( 39970 4 0 5; 30 2 70 738)~~

摘　　要：采用诱导卵泡发育、卵母细胞培养、制备减数分裂染色体标本等技术 ,对棕色田鼠两种雌体 (XO、XX)的减数分裂进行了比较研究。研究结果表明 :棕色田鼠XO和XX雌体在表型和内外生殖器结构上无差异 ;在用孕马血清促性腺激素刺激XO雌体和XX雌体后 ,两者卵巢上的有腔卵泡数目相近 ;两者产生的卵母细胞数目、生发泡破裂数目以及第一极体排放数目 ,统计学分析差异都不显著。同时表明XO雌体的减数分裂过程正常 ,能得到卵母细胞中期Ⅱ分裂相。据此我们认为 :雌体 (XO)与雌体 (XX)的卵巢功能都正常 ,两者的卵母细胞均具有较强的成熟能力且无差异。因此 ,棕色田鼠XO个体是核型异常、育性正常的雌体。另外 ,具有三种遗传性别的棕色田鼠可能是处于XX/XY与XO/XY性别决定系统进化途径的中间类型 。We used the technique of stimulating follicle to develop, oocyte cultur e, preparing the chromosome specimen of metaphase Ⅱto compare the meiosis of XO female individuals with XX female individuals in M. mandarinus. The results sho wed no difference in the phenotype, the gonad and the genitalia between XO and X X female individuals in M. mandarinus. The numbers of the antral follicles of o varies in both female XO and XX stimulated with PMSG were approximately equival ent. There was no significant difference in the amounts of oocytes,GVBDs and PB Ⅰ between XO and XX female individuals. The XO female individuals could accompl ish meiosis successfully and we could get the chromosome specimen of metaphase Ⅱ from them. The results suggested that the functions of ovaries of XO and XX f emale individuals are both available, and the oocytes of them all have good abil ity to mature. Thus the XO female individuals had abnormal karyotypes and good a bilities of reproduction. The paper also discusses the evolution of the sex dete rmination system in M. mandarinus. In addition, Microtus mandarinus with three t ypes of inherited sexes may be the interim group between XX/XY and XO/XY sex det ermination systems in the evolutional process, which sex determination system is still in the state of transformation .

关 键 词：棕色田鼠 卵母细胞 减数分裂 XO雌体 

分 类 号：Q953[生物学—动物学]