摘要
为分析甘肃金鳟遗传资源状况,研究利用18个微卫星DNA标记,对甘肃金鳟、日本金鳟和道氏虹鳟3群体各50尾个体进行了遗传分析,以评价甘肃金鳟遗传资源状况并研究其与日本金鳟和道氏虹鳟遗传分化情况。结果表明甘肃金鳟具有较丰富的遗传变异,15个微卫星DNA座位共获得了51个等位基因,有效等位基因数(Ne)为1.13,多态信息含量(PIC)为0.440,平均观察杂合度(Ho)和期望杂合度(He)分别为0.430和0.498。在Hardy-Weinberg平衡条件下,进行了P检验,发现3个群体均有位点发生了显著偏离;对3个群体进行了Fst值计算,表明群体间存在着一定程度的遗传分化,但遗传变异绝大部分存在于品种内。综合分析,认为甘肃金鳟遗传性状基本稳定,遗传变异度较高,遗传多样性相对丰富,具有较大的遗传潜力,与道氏虹鳟和日本金鳟群体间分化明显,人工选育对群体的遗传变异产生了一定的影响。研究结果对甘肃金鳟的保种、选育及其合理的推广应用具有一定的指导作用。
Oncorhynchus mykis is an important reared freshwater species, which has been cultured for more than thirty years in Gansu Province, China. Due to the ecological conditions, different feeding manners, the various breeding goals and some native breeds had been formed in the past years, such as Gansu golden trout, which had past the National Aquaculture Species Identification Committee identifying and was recommend as the species reared in the northwestern areas. However, the genetic differentiation and the genetic variability are still unknown. In order to get insight into the genetic variability in its population and provide the genetic background and guidance for its conservation and utilization, 20 microsatellite DNA markers were applied to analyze genetic diversity and genetic differentiation. Genome DNA was extracted from each 50 individuals in Donaldson rainbow trout, Albino rainbow trout and Gansu golden trout in total 150 individuals. Each fish was extracted from ethanol-preserved caudal fin by using phe-nol-chloroform method. The PCR was performed in a 25 μL reaction and the products were isolated by electrophoresis on 10% polyacrylamide gel and visualized by silver staining. The data were calculated and analyzed by statistic method. 18 microsatellite primers were successfully amplified, 13 loci with reasonable polymorphism in the three populations. And there were a large range of genetic variation existing in Gansu golden trout. The number of alleles in these loci ranged from 2 to 7. 51 alleles was obtained; the mean number of alleles was 3.00; the value of mean polymorphism in-formation content （PIC） was 0.440, the PIC value was more than 0.5 in locus AF346692, AF375011, AF352739, AF352746, AF352747, AF352751, AF352756, AF352763 and AF352765; the PIC value was more than 0.25 and less than 0.5 in locus AF352767 and AF352762; the PIC value was less than 0.25 in locus AF352750 and AF352749. The observed heterozygosity （Ho） and the expected heterozygosity （He） were calculated based on frequencies of genotypes and alleles of each microsatellite locus, the value of average observed heterozygosity （HO） and expected heterozygosity （He） were 0.498,0.498 respectively, which showed that Gansu golden trout had relatively abundant genetic diversity. Genetic distance analysis showed that the largest distance was between Donaldson rainbow trout and Gansu golden trout and the smallest distance was between Albino rainbow trout and Gansu golden trout. Furthermore, it was found that some microsatellite loci of the three breeds deviated from Hardy-Weinberg equilibrium, where the majority of the variance in the Oncorhynchus mykiss was within populations （80.7%）, and small proportion was among populations （19.3%）. The medium level of overall genetic diversity and medium Fixation Index （Fst=0.193） indicated that the On-corhynchus mykis reared in Gansu had relatively medium genetic variation. Obviously, the genetic characteristics and the genetic status of Gansu golden trout are getting stable. The genetic differentiation was significant among the three breeds, and selective breeding impacted genetic variations on the breeds. The results provided the guidance for its breeding, spreading, conservation and utilization.
出处
《水生生物学报》
CAS
CSCD
北大核心
2010年第2期262-269,共8页
Acta Hydrobiologica Sinica
基金
甘肃省自然科学基金"甘肃金鳟遗传多样性研究"(0710RJZA096)资助
关键词
甘肃金鳟
微卫星
遗传分化
遗传多样性
Gansu golden trout
Microsatellite
Genetic differentiation
Genetic diversity
