Genetic diversity of Jiangsu native chicken breeds assessed with the mitochondrial DNA D-loop region

1. The objective of this study was to determine the origin and evolution of chickens from 5 native breeds that are traditionally raised in Jiangsu Province.2. To address this question, the complete mitochondrial DNA D-loop sequence of 149 chickens from 5 native breeds of Jiangsu Province was analysed.3. Sequence read lengths of the native breeds were 1231 to 1232 bp, with a single-base deletion from the 859 bp site in the 1231 bp haplotype. A total of 33 variable sites that defined 19 haplotypes were identified. The average haplotype diversity and nucleotide diversity were 0.8620.017 and 0.005910.00135.4. Phylogenetic analysis showed that genetic structure of the mtDNA haplotypes of Jiangsu chickens are distributed across 5 clades (haplogroups): Clades A, B, C, D, and E. However, most of the individuals characterised in this study belonged to clades A and B.5. The results of this study indicate that Jiangsu chicken populations have relatively low nucleotide and haplotype diversity and likely share 5 common maternal lineages.