奥利亚罗非鱼(♀)×鳜(♂)远缘杂交子代的遗传结构

Genetic constitutions of distant hybridization offsprings between Oreochromis aurea(♀)×Siniperca chuatsi(♂)

采用RAPD和测序的方法,对奥利亚罗非鱼(Oreochromis aurea)(♀)与鳜(Siniperca chuatsi)(♂)的杂交子代组合与父母本的遗传关系进行研究,探讨远缘杂交双亲对子代遗传结构的影响。其中,杂交子代包括A、B、C 3个组合,A组合为奥利亚罗非鱼与鳜杂交的F1代;因A组合无雄性,将其与奥利亚罗非鱼(母本)的雄性回交,所得子代为B组合;C组合为B组合间兄妹交的自交子代。结果表明,奥利亚罗非鱼、鳜、A、B和C组合的多态位点比例分别为19.32%、15.30%、41.33%、29.80%和32.31%。奥利亚罗非鱼和鳜间的遗传相似性系数和遗传距离分别为0.288 5和1.243 2。A、B、C组合与父本的遗传相似性系数分别为0.343 4、0.293 7、0.328 7,遗传距离分别为1.068 9、1.225 1、1.112 5;与母本的遗传相似性系数分别为0.903 7、0.916 8、0.922 5,遗传距离分别为0.101 3、0.086 9、0.080 7。本研究中找到一个在杂交A、B及C组合均出现的与父本共有的条带。测序结果表明,该条带长362 bp,在子代与父本中的一致性为100%。研究结果说明,奥利亚罗非鱼和鳜杂交子代中导入了父本遗传物质,导致子代组合的多态性增加,与父本的遗传差异变小,而且,这些遗传物质能稳定进行遗传;随着A组合与母本的回交及B组合的自交,又使得杂交子代的遗传结构向母本靠近。[中国水产科学,2007,14(1):32-38]

There were a variety of applications on distant hybridization of fish, such as heterosis utilization, sex control, polyploid induction, gynogenesis and androgenesis,etc. So,many studies about distant hybridization of fish have been performed for a long time. However, most of these studies focused on inter-subfamily, intergeneric and interspecific hybridization. Successful interfamily and interorder hybridization of fish was sporadicly reported. Oreochromis aurea and Siniperca chuatsi belong to different families. Since 2001, the hybridization between them has been performed successfully. Up to now, a series of hybridization offsprings were obtained. We investigated the genetic relationship between offsprings of O. aurea （ ♀ ） × S. chuatsi （ ♂ ） and their parents by using RAPD and sequencing methods to test the effect of distant hybridization on the genetic constitutions of three offspring groups which included groups A, B and C. Group A was F1 of O. aurea （ ♀ ） × S. chuatsi （ ♂ ）. Group B was backcross offsprings between A and male of O. aurea because no male existed in group A. Group C was derived from self-cross offsprings of gruop B. The results showed polymorphic locus ratios of S. chuatsi, O. aurea ,and groups A,B and C were 19.32% ,15.30%, 41.33% ,29.80% and 32.31% ,respectively. The genetic identity and distance between O. aurea and S. chuatsi were 0.288 5 and 1. 243 2, respectively. Genetic identity between groups A, B and C and S. chuatsi were 0.343 4,0.293 7,0.328 7;genetic distance were 1.068 9,1.225 1 and 1. 112 5,respectively. Genetic identity between groups A, B, C and O. aurea were 0.903 7,0.916 8,0.922 5; genetic distance were 0.101 3,0.086 9 and 0.080 7 ,respectively. One primer （F12） could be amplified into 1 special RAPD band on groups A,B and C which was the same as that of S. chuatsi and did not exist in O. aurea. This band was 362 bp. The sequence identity of this band was 100% between offsprings and S. chuatsi. The conclusion is that some genetic substances of father are induced into offsprings of distant hybridization, and make the genetic constitutions of offsprings more polymorphic and closer to faternal parent＇ s. Furthermore, these genetic substances could transfer to the next generation. However, because of backcross between A and O. aurea and self-cross of B, the genetic structures of offsprings are more and more close to the maternal parent.