The investigation of genetic diversity and evolution of Daweishan Mini chicken based on the complete mitochondrial (mt)DNA D-loop region sequence

This study evaluated the genetic diversity and origin of Daweishan Mini chickens using mtDNA sequence polymorphism. Blood samples from 30 Daweishan Mini chickens were collected. The complete D-loop was PCR amplified, sequenced and compared with the DNA data of five Red Junglefowl (Gallus gallus) subspecies. Eighteen variable sites that defined six haplotypes were observed. The six haplotypes were clustered into four clades (A, B, D and E), of which clade A and B were dominant. Clades A and B were clustered with G.g. spadiceus, indicating these two clades may have originated from this subspecies. These results show there is diversity in the middle of the mtDNA D-loop, and indicate there are multiple maternal origins for Daweishan Mini chickens. It appears that G.g. spadiceus contributed more to the evolution of the Daweishan Mini chickens breed than the other four subspecies tested here.