鲫鲤杂交品系异源染色体的减数分裂特征研究

鲫鲤杂交能突破F1生殖难关产生可育的杂交品系。解析该杂交鱼突破生殖难关过程中异源染色体的减数分裂特征，可进一步探究杂交品系稳定传代的内在机制，在生物进化研究和育种实践方面都具有重要意义。本研究一方面选定染色体标记因子，包括着丝粒标记因子（263bp着丝粒定位重复序列）；染色体臂间标记因子（5SrDNA；异源四倍体鲫鲤BAC克隆）；染色体末端标记因子（Telomeres）、染色体交叉标记因子（MLH1）及联会复合体标记因子（SYCP1、SYCP3）等，对鲫鲤杂交鱼生殖细胞减数分裂配对、联会、重组（交叉）、分离过程进行系统的FISH和免疫荧光检测，以期待解析杂交鱼异源染色体减数分裂的遗传定位特征；另一方面，选用减数分裂关键基因spo-11, mlh1等在杂交鱼与异源双亲间进行分子遗传特征比较，探究源自异源双亲的减数分裂因子在杂交品系传代中是否存在选择压力，为进一步的基因功能分析奠定基础。

The F1 hybrid fish of red crucian carp (Carassius auratus red var.) (♀; 2n = 100)×common carp (Cyprinus carpio L.) (♂; 2n = 100) could break through the reproductive barriers, which made them can produce bisexual hybrid offspring and strains. Analyzing the characteristics of heterogenetic chromosome meiosis in hybrids could give a view about why the hybrids can produce stable hybrids, which is of great significance in biological evolution research and fish genetic breeding. The study would first commit to screen chromosomal loci factors in different chromosomal region, including centromere loci (263bp repetitive sequence), chromosome arm loci (5S rDNA and BAC clones), terminal loci (Telomeres repetitive sequence), chromosomal chiasmata loci（MLH1）and synaptonemal complexes loci（SYCP1 and SYCP3). Using above marked factors, the chromosomal localization performed by FISH or IF, would be carried out to observe the characteristics of pairing, synapsis, recombination and separation in meiosis of hybrid fish. Then, some key factories of meiosis such as spo-11 and mlh1 would be analyzed to study the molecular genetic relationships between hybrids and original parents, which could explore whether the meiosis genes have selective pressure in the hybrid strains and would set base for the following study of meiotic gene function in hybrid fish.