Genetic Diversity Of Varied Tit (Parus Varius) Inferred With Mitochondrial DNA Control Region And Nuclear Microsatellite Markers

Parus varius (Passeriformes, Paridae, Parus), is a kind of small cavity-nest forest birds and monomorphic with obviously narrow distribution. P.v.varius distributes narrowly in Chinese mainland, such as the middle, eastern, southern mountains of Liaoning province and partial mountains of Jilin province, which is contiguous to eastern mountains of Liaoning province. The limited distribution leads to rarely researches on P.v.varius in China. Furthermore, analysis of genetic diversity based on multi-gene markers has never been reported. Genetic diversity, one kind of important biological resources, is the foundation of protecting species development and continuation of population.Here, I report the results of genetic diversity of P.v.varius in Chinese mainland based on the analysis of mitochondrial DNA control region and nuclear microsatellite markers:1) 529 bp in length were sequenced in mitochondrial DNA control region of 68 individuals. Fourteen variations in all were detected, including 11 singleton variable sites and 3 parsimony informative sites. Genetic diversity was low based on mt DNA control region of P.v.varius, with 0.0017 for nucleotide diversity (Ï€) and 0.5328 for haplotype diversity (h). I attribute the low genetic diversity of this bird to its narrow distribution and small population in the long-term history. There were no population expansion events or bottleneck effect in P.v.varius as indicated by the results from neutrality test and mismatch distribution. Both of the phylotypes trees revealed that P.v.varius in Chinese mainland belongs to one population without obvious differentiation.2) The number of allele was 6~16 with a mean value of 11.78. The average observed heterozyosity, the average expected heterozyosity, and polymorphic information content (PIC) across the nine loci was 0.651, 0.779 and 0.755 respectively. Genetic diversity is high based on nine nuclear microsatellite markers of P.v.varius. The observed genotype frequencies at four loci were consistent with Hardy-Weinberg Equilbrium (HWE) and the remaining five loci were significantly deviated from HWE. The results may be resulted from null allele and genetic drift. Both graphical assessment of allele frequency distributions and allele frequency distribution for gaps showed that there was no bottleneck in the recent history of P.v.varius.In conclusion, results from the present work indicate that genetic diversity of mitochondrial DNA control region was lower in P.v.varius than in other related birds, which may be accounted for by its narrow distribution and small population in the history. However, the population remains stable and shows no bottleneck effect in recent decades.