二倍体雌核发育鲫鲤卵子发生的DNA含量和细胞学分析  

DNA contents and cytological analyses of oogenesis of the dipoid gynogenetic progeny of allotetraploid hybrids

作　　者：张纯[1] 刘少军[1] 伍艳红[1] 刘筠[1] 

机构地区：[1]湖南师范大学生命科学学院、教育部蛋白质化学与鱼类发育生物学重点实验室,湖南长沙410081

出　　处：《水产学报》2015年第1期1-7,共7页Journal of Fisheries of China

基　　金：国家自然科学基金重大国际合作项目(31210103918);国家自然科学基金(31201980/30901100);湖南省生物发育工程及新产品研发协同创新中心项目(20134486);湖湘青年科技创新创业平台培养对象项目;湖南省科技计划(2014FJ3084)

摘　　要：以产生单倍体卵子的二倍体雌性红鲫为对照,对远缘杂交起源的二倍体雌核发育鲫鲤早期卵巢组织中的生殖细胞进行了流式细胞术分析,在此基础上结合组织学切片方法和染色体制片,对相应的卵巢组织细胞学观察和生殖细胞减数分裂特征进行了探讨。结果显示,雌核发育二倍体鲫鲤卵母细胞的DNA含量呈现两个主要的峰值,检测样本中的2号峰值显示的DNA含量是二倍体红鲫卵母细胞的1倍,代表减数分裂前染色体数未加倍的细胞群,其减数分裂Ⅰ前期分裂相呈现同源染色体部分配对,该细胞群在组织学切片上呈现空泡化等败育现象;另外,检测样本中的3号峰值显示的DNA含量是二倍体红鲫卵母细胞的2倍,代表减数分裂前染色体数已加倍的细胞群,其减数分裂Ⅰ前期分裂相呈现染色体数目加倍的完整的染色体配对,该细胞群由于染色体数加倍,可以越过杂种鱼的异源染色体之间的减数分裂配对障碍,正常发育为体积不断增大的初级卵母细胞,为产生后续的染色体数不减半的二倍体卵子奠定基础。该结果丰富了不减数配子的发生机制研究,在鱼类遗传育种方面具有重要意义。Formation of unreduced eggs has been reported in several interspecific hybrids of teleosts. These results suggested that a genomic conflict due to a hybrid event may trigger an atypical mode of reproduction, such as formation of unreduced gametes. The diploid gynogenetic progenys of allotetraploid hybrids of red crucian carp （ Carassius auratus var. red） x common carp （ Cyprinus carpio L. ） （ abbreviated as G） produced diploid eggs, which have been identified by chromosomal counting of germ cells, fertilization observation of gametes and ploidy detection of progeny. In this paper,DNA contents and cytological studies on oogenesis of G was detected by Flow Cytometry, tissue sections and chromosomal observations, with dipoid red crucian carp as controls. The results showed that the DNA contents of oocytes in G were showed with two main peaks. The peak one with the lower value was consistent and the other peak value was double with that of oocytes in RCC,which were deduced as different type of primary oocytes by tissue sections observations and chromosomal observations. The oocytes with lower peak values showed the mainly smaller volume of primary oocytes, in which there were some cavitation-like abnormal oocytes, exhibiting partical pairing at the pachytene stage, they were deduced as the primary oocytes without chromosomal doubling. Such other oocytes with higher peak values showed a few larger volume of primary oocytes in stage 1I, which could perform normal development with normal chromosomal pairing in meiosis I , and were deduced as the primary oocytes with chromosomal doubling. The results enriched the research data of mechanism of unreduced gametes,being of great significance in fish genetic breeding.

关 键 词：二倍体杂种鱼 卵母细胞 减数分裂 不减数配子 流式细胞术 

分 类 号：Q321.3[生物学—遗传学] S917.4[农业科学—水产科学]