罗非鱼微卫星DNA指纹图谱的构建

Establishment of DNA fingerprinting of tilapia with microsatellite

采用微卫星DNA指纹图谱技术对奥利亚罗非鱼、尼罗罗非鱼和橙色莫桑比克罗非鱼进行品种鉴定和遗传多样性分析。从103对罗非鱼微卫星引物中筛选出82对多态性高、带型清晰稳定的引物,用这82对引物检测3种罗非鱼的遗传结构,共检测到605个等位基因,平均等位基因数7.37个,数据经Popgen32计算和EXCEL工具作图,构建3种罗非鱼的DNA指纹数据库,并绘制了DNA指纹图谱模式图。结果显示,奥利亚罗非鱼、尼罗罗非鱼和橙色莫桑比克罗非鱼的平均观测杂合度分别为0.179 6、0.530 1和0.312 2,平均期望杂合度分别为0.203 2、0.678 6和0.291 3,平均多态信息含量分别为0.075 4、0.608 3和0.152 8,由此可见,尼罗罗非鱼群体的遗传多样性水平最高,奥利亚罗非鱼群体遗传多样性最低。同时筛选得到16对具特异性条带的核心引物组合可将3种罗非鱼完全区分,每个位点可在其中一种罗非鱼中扩增出独有的条带,从而将这种罗非鱼与其它两种区分开来,将16对特异引物的图谱数据转化成计算机可以识别的数码指纹,可以方便地应用于罗非鱼及其杂交种的鉴定研究。为解决罗非鱼品种混杂遗传渐渗问题和保护罗非鱼种质资源提供技术支撑。

Microsatellite DNA fingerprinting technology was used to investigating the genetic variation and germplasm identification within three tilapias of Oreochromis aureus,O. niloticus and red O. mossambicus. 82 pairs of primers which could give stable and polymorphic amplification profiles were screened out from 103 microsatellite loci and used to analyze the genetic structure of three varieties. Totally, 605 alleles of microsatellite loci were obtained and the average number of alleles was 7.37. Additionally, microsatellite DNA fingerprinting database of three tilapias was established based on the results of alleles of microsatellite loci by Popgen32 software package and illustrative patterns were constructed by EXCEL. The results showed that, the mean value of observed heterozygosity of O. aureus, O. niloticus and O. mossambicus was 0.179 6, 0.530 1, 0.312 2, the mean value of expected heterozygosity was 0.203 2, 0.678 6, 0.291 3, and the polymorphism information content （PIC） was 0.075 4, 0.608 3, 0.152 8, respectively. It indicated that, the genetic diversity of O. niloticus was the highest and O. aureus was the lowest. Then 16 pairs of primers that can distinguish one variety tilapia from the others were screened out as the core primers for tilapia germ plasm identification. The amplified data from 16 pairs of special primers were transformed to the application platform of digital microsatellite DNA fingerprinting, which could be used to identify tilapia species. This result could provide a technique for solving the problem of germplasm farrago for tilapia.