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 0.862 ± 0.017 and 0.00591 ± 0.00135. 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.