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The genetic diversity of eight domestic pigs was analyzed using a hypervariable fragment in the mitochondrial (mt) DNA control region; a portion of the hypervariable control region (515 bp) was sequenced from 153 samples. Haplotype diversity and nucleotide diversity in Yushan black pig populations were significantly higher than other populations (p < 0.01). A neighbor-joining tree was constructed from domestic pig mtDNA and five wild pigs. The results indicate that there are only small differences among individual pigs from different regions. Networks of the domestic pigs were constructed to better visualize the relationships between sequences. Each core haplotype was surrounded by a star-like pattern, consistent with recent population expansion.

The loss of local chicken breeds as result of replacement with cosmopolitan breeds indicates the need for conservation measures to protect the future of local genetic stocks. The aim of this study is to describe the patterns of polymorphism of the hypervariable control region of mitochondrial DNA (HVR1) in domestic chicken in China's Jiangxi province to investigate genetic diversity, genetic structure and phylo-dynamics. To this end, we sequenced the mtDNA HVR1 in 231 chickens including 22 individuals which belonged to previously published sequences. A neighbor-joining tree revealed that these samples clustered into five lineages (Lineages A, B, C, E and G). The highest haplotype diversity and nucleotide diversity were both found in Anyi tile-liked gray breed. We estimated that the most recent common ancestor of the local chicken existed approximately 16 million years ago. The mismatch distribution analysis showed two major peaks at positions 4 and 9, while the neutrality test (Tajima's D = -2.19, p < 0.05) and Fu's F-statistics (-8.59, p < 0.05) revealed a significant departure from the neutrality assumption. These results support the idea that domestication of chickens facilitated population increases. Results of a global AMOVA indicated that there was no obvious geographic structure among the local chicken breeds analyzed in this study. The data obtained in this study will assist future conservation management of local breeds and also reveals intriguing implications for the history of human population movements and commerce.