The Complete MtDNA Genome, Genetic Diversity And Population Structure Of Triplophysa Strauchii(Cypriniformes: Cobitidae)

In the present work, the complete mitochondrial genome of the Triplophysa strauchii(Cypriniformes: Cobitidae) is sequenced and placed, the phylogenetic analysis with another individual of Triplophysa fishes was carried out. The mitogenome is 16,590 bp in length, consisting 13 protein genes, 22 tRNA genes, 2 rRNAs genes, and 2 noncoding regions. The total base composition is 28.26%, 28.49%, 25.42% and 17.82% for A, T, C and G, respectively. All genes were encoded on the heavy strand except for ND6 and 8 tRNA genes. The genetic, population structure of T. strauchii from four locations of the Ili River were examined based on mitochondrial DNA sequences and Microsatellite loci for 112 individuals of T. strauchii were incurred by utilizing Polymerase Chain Reaction process and sequencing. The results exhibited that T. strauchii populations had eminent gene diversity and moderate nucleotide diversity, also the genetic variety of this species was at a moderate level. After sequencing, 179 duplicates were found containing microsatellite recurrence sequences. Finally, PCR primers were contrived for 52 loci successfully, of which 8 loci showed polymorphic and 15 ones were monomorphic. 8 fluorescent primer pairs were used for evaluating T. strauchii individuals, the number of alleles and polymorphism information content(PIC) was varied from 8 to 25, 0.41 to 0.92. Analysis of neutral test and mismatch distribution confirmed that T. strauchii might have experienced a late population expansion. Fst analysis indicated significant genetic differentiation among populations of different areas. The hierarchical analysis of molecular variance(AMOVA) also showed substantial genetic diversity among these populations. In this study, we compared the utility of two DNA markers(four mtDNA, 16 S, COI, COII, and CR) and(Microsatellite) to evaluate the population structure and genetic diversity of this species(T. strauchii). The COII gene diversity shows a lower rate of mitochondrial evolution than the 16 S, COI and CR genes. In summary, our results propose that using DNA markers and nuclear DNA for genetic structure and diversity in the T. strauchii is a mostly valid approach, and that the mtDNA(16S, COI and CR genes) and SSRs loci are better DNA markers than the COII gene. This study would be essential to constitute scientific schemes for efficient conservation and long term development of wild resources of T. strauchii.