Study On Genetic Diversity Of Qinghai-lake Naked Carps

In this paper,the genetic diversity of Qinghai-lake Naked Carps was studied for the first time by methods of chromosome karyotype,protein (isomzy) electrophoresis and mtDNA RFLP. The results of chromosome karyotype indicated that:?The diploid chromosome number of Qinghai-lake Nakked Carp was 2n=92 that comprised of 18 metacentric chromosomes,18 submetacentric chromosomes,16 telocentric chromosomes and 40 acrocentric chromosomes,and the karyotype formula was 18nvH8snvH6st+40t,NF=128. With Compared to other species of Schizothoracinae fishes,the diploid chromosome number of Qinghai-lake Nakked Carp was equal to Schizothorax waltoni,S. o'connori,Oxygymnocypris stewarti,Schizoygopsis pylzovi and Chuanchia labioza. This showed that these Schizothoracinae fishes which diploid chromosome number were 92 were likely to have experienced similar ecological environment as they involved into special Qinghai-Tibten plateau-adaptive species gradually. ?As same as most other Schizothoracinae fishes,Qinghai-lake Nakked Carps may be tetraploid that already were diploidization;?Qinghai-lake Nakked Carps arose from some primitive Barbinae fishes,which gradually became special population adapting to high altitude environment by involvement and natural selection,On protein electrophoresis,out of 20 protein loci among 132 individuals in the present experiment,only T MDH> AMY\ EST and POD showed polymorphism. Among them Tf> MDH,AMY and EST were all controlled by one pair of alleles,the electrophoretogram of POD showed more complicated and we didn't further studied. The degree of genetic variability in Qinghai-lake Naked Carps was estimated to be P = 0.025 and H = 0.095. As a whole,h was lower than horsesjiigher than goats,sheep and catties.On mtDNA RFLP,among the 30 Qinghai-lake Naked Carps,7 restriction endonucleases of BamHI (A3) 3d I (A,B) andPvuII (A3) showed polymorphism and Ava I (A) showedmonomorphism,which could be sorted into 4 haplotypes and haplotype I was primary (because haplotype I accounted for eighty percent in the population) that,namely,Ava I-A,Bam H I-A,Bel I-A and Pvu I-A,The genetic distance (G) among haplotypes ranged from 0.011 to 0.10,and the value of nucleotide diversity î–¯) in Qinghai-lake Naked Carps population was 0.0043. The results suggests that the 30 Qinghai-lake Naked Carps in this experement may have four female origins.