Genetic Diversity Of Five Geographical Populations Of Pelteobagrus Fulvidrau In The Middle And Lower Reaches Of The Yangtze River And The Study Of MSTN Polymorphism

Pelteobagrus fulvidraco, which belongs to Pelteobagrus of Bagridae of Siluriformes, is widely distributed over Heilongjiang River, Yellow River, Yangtze River and Zhujiang River. As one of the most important economic freshwater fish, it is favorite in customers with tender fish, good taste, high protein, low fat and high nutrition. Our country used to have rich Pelteobagrus fulvidraco resources, but as a result of intemperate fishing and environment polluting in recent years, they have been destroyed to some extent. Domestric scholars have some research in the grouping genetic structures and breeding of Pelteobagrus fulvidracos except its new strains’collecting, so, Freshwater Fisheries Research Institute of Jiangsu province does something.In this research, we collect wild Pelteobagrus fulvidracos from Cao Lake, Ge Lake, Hongze Lake, Poyang Lake and Tai Lake, by sequence the mitochondrial D-loop and Cyt b genes of the Pelteobagrus fulvidracos and combining with SSR, to study the genetic varieties and grouping genetic structures of Pelteobagrus fulvidraco in these five different geographical varieties. Conclusions are showing next:1.The total mitochondrial D-loop of yellow catfish from5populations were sequenced. The result showed that there were151variable sites and24parsimony informative sites in890sites.72haplotypes were discovered from143individual. The average Haplotype diversity index and Nucleotide polymorphism index was0.951±0.011and0.00614±0.00087respectively. The analysis of genetic distance between5populations showed that the various genetic distance among5populations are small of0.00427-0.00989. The genetic distance between Lake Poyang and others were larger relatively of0.00758-0.00989, while it between Lake Ge and Lake Chao was the minimum of0.00427. The overall genetic differentiation index (Fst) of5populations was0.0896(P<0.01), which indicated that variation came from intragroup was91.04%and it came from intergroup was8.96%. The gene flow coefficient (Nm) between5populations was2.22, which showed revealed the existence of certain gene flow between5populations.2. Abstract:The mtDNA cyt b gene of yellow catfish from five lakes in the middle and lower reaches of the Yangtze River was amplified and sequenced. The result showed that the average contents of A+T were a little higher than that of G+C in the aligned sequences of955bp,54variable sites were detected, and37haplotypes were recovered. The haplotype diversity and nucleotide diversity were0.945±0.018and0.00419±0.00043, respectively. The genetic distance between Taihu population and Gehu population displayed the highest, up to0.00651, while that between Poyang lake population and Chaohu population was the lowest to00375. The fixation indices (Fst) of analysis of molecular variance (AMOVA) among populations was0.0684(P<0.05), which showed no significant population structure. The phylogenetic tree of cyt b built with MEGA4.1showed that five populations were not clustered into clades based on genetic distance. There was extensive general flow between yellow catfish populations from five lakes in the middle and lower reaches of the Yangtze River.3. For researching hereditary variabilities and genetic relationships of the yellow catfish populations in five lakes(Chaohu lake, Gehu lake, Hongze lake, Poyang lake and Taihu lake) in the lower reaches of the Yangtze River, thirteen SSR primer pairs were used to extend the DNA genome of these five yellow catfish populations. The experiment resulted that the each number of allele was between3to8while the average number was4.38and the effective allete averaged between1.22to5.43. The observed and expected herterozygosity averaged0.4105to0.4892and0.46to0.55respectively of the five populations while the maximum and the minimum were found in Chaohu lake and Gehu lake population(PIC=0.55) and Poyang lake population (PIC=0.46). The coefficient of dissociation and gene flow was0.00907and4.4347respectively. The UPGMA dendrogram told that Hongze lake population got together with Taihu lake population first, then, Gehu lake population and Chaohu lake population and Po-yang lake population was its last choice.Moreover, Eight SNP locus of high polymorphism were tested from the MSTN whole sequence of one hundred six months yellow catfish by directly sequence the PCR production. Otherwise, analysis the relationship between body weight. The result showed that seven sites were located in uncode area as the other one is in code area. But, the nucleotide mutation, which located in code area, were synonymous mutation. In these eight SNP locus, three genotype have distinctly correlation with Pelteobagrus fulvidracos’ weight:IJ is in positive correlation with the weight as NN and OP are in the contrary. We could try to use these three locus to make molecular marker assisted breeding in the Pelteobagrus fulvidracos’ breeding.