Genetic structure of Chinese sucker population Myxocyprinus asiaticus in the Yangtze River based on mitochondrial DNA marker
The sequencing analysis of the mitochondrial DNA control region (mtCR DNA) was performed to assess the genetic divergence and population structure of the Chinese sucker Myxocyprinus asiaticus (Cypriniformes Catostomidae) using four sample lots from natural populations of the Yangtze River. The mtCR DNA sequences of approximately 920 base pairs were obtained. A total of 223 nucleotide positions were polymorphic, and these defined 39 haplotypes. Of the 39 haplotypes, 37 (90%) were not shared, and among the populations as a whole there was little sharing of haplotypes. The average haplotype diversity (0.958) and the average nucleotide diversity (0.052) indicated a higher level of genetic diversity of Chinese sucker through the river. Analysis of molecular variation ( amova) of data revealed significant partitioning of variance (P < 0.001) among populations (60.29%), and within populations (39.71%). The topology according to the neighbor joining and maximum parsimony methods showed mosaic composition of the 39 haplotypes, suggesting that the populations were not completely divergent. The pairwise F statistic values, however, indicated that the population structuring existed to some extent among the geographic populations. There was a positive relationship between the aquatic distance and the genetic distance (Fst) among the populations (P < 0.05). Based on our data, it is suggested that genetic drift, gene flow, and stochastic events are the possible factors influencing the population structure and genetic variation.
Document Type: Research Article
Affiliations: 1: Animal Development and Genetic Laboratory, College of Life Sciences, Wuhan University, Wuhan 430072 2: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430071, China 3: Laboratory of Applied Population Genetics, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi 981-8555, Japan
Publication date: 2004-06-01