Genetic Diversity Of MtDNA Sequences In Chinese Indigenous Chickens

In the present study, the sequences of hyper-variable segment I of mitochondrial DNA D-loop (mtDNA D-loop HVS-I) of 52 individuals belonging to three indigenous chicken populations of Gansu (Jingning chicken, Huining chicken and Minqin chicken) were determined. Population genetic diversity and phylogeny were assessed for these individuals together with sequences of 596 individuals belonging to 59 Chinese indigenous chicken populations retrieved from the GenBank and of 92 individuals belonging to eight Chinese indigenous chicken populations sequenced by the Insternatioal Livestock Research Institute through collaboration with the South China Agricultural University. Some observations and conclusions are made as follows:1. In 397 bp long sequences of the mtDNA D-loop HVS-I of 52 individuals belonging to three indigenous chicken populations of Gansu, there are 15 polymorphic sites between nucleotides 167 and 367, which account for 3.78% of the nuclotides sequenced.2. The number of haplotypes of Jingning chicken, Huining chicken and Minqin chicken are six, three and three, respectively, defined using the nucleotide variations. Using Dnasp 4.10.3 software, the haplotype diversity (H), nucleotide diversity (Pi) and mean number of differences between all pairs of haplotypes in the sample (K) of the Jingning chicken, Huining chicken and Minqin chicken were estimated. The results show that these three parameters of the Jingning chicken are the highest, indicating a richer genetic diversity of Jingning chicken compared to the other two populations.3. There are 10 haplotypes in the three indigenous chicken populations of Gansu. Phylogenetic analysis of the haplotypes suggests that these haplotypes be considered as three clades. This means that the Jingning chicken, Huining chicken and Minqin chicken of Gansu have three maternal lineages.