Genetic Relationships among Different Breeds of Chinese Gamecocks Revealed by mtDNA Variation

There are currently five primary breeds of Chinese gamecock, the Henan, Luxi, Tulufan, Xishuangbanna and Zhangzhou. Though there is historical evidence of cockfighting in China dating as far back as 2,800 years., the origin and genetic relationships of these breeds are not well understood. We used sequence variation from the mtDNA cytb gene and control region (1,697 bp) to examine the domestication history and genetic relationship of the Chinese gamecock. From 75 samples (14-16 per breed) we found 34 haplotypes, and 45 variable nucleotides. Phylogenetic reconstruction indicated multiple origins of the gamecock breeds. The breeds in the north and center of China, Tulufan, Luxi and Henan, clustered together in a haplogroup and may have the same ancestor. However the southern breeds, Zhangzhou and Xishuangbanna clustered into two isolated haplogroups., suggesting another two origins of Chinese gamecock. Meanwhile, extensive admixture was also found because samples from different breeds, more or less, were always grouped together in the same clades. Based on these results, we discuss the possibilities of multiple origins of gamecock breeds, from both ancestral gamecocks as well as other domestic chickens and red jungle fowl.