Complete mitochondrial genome of Qingyang donkey ( Equus asinus).

The present study aimed to report the entire mitochondrial genome of Qingyang donkey ( Equus asinus). Donkeys play an important role in the daily lives of human beings. The population of Chinese donkey breeds has undergone an enormous decline with the advance of agricultural mechanization, rapid development of transportation and introduction of new different breeds over the past few decades. As a result, a large number of donkey breeds are close to extinction, especially Qingyang donkey. Mitochondrial DNA is used as a molecular tool in research on biodiversity conservation and sustainable utilization of biological resources. The circular genome sequenced using the Illumina Hiseq 2500 platform was 16,568 base pairs (bp), containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a non-coding control region. The initiation site of the L-strand replication origin, 32 bp in length, was between tRNA-Asn and tRNA-Cys. The base composition of the genome was A (32.4%), C (28.7%), G (13.2%) and T (25.7%) with an A+T content of 58.1%. Molecular phylogeny demonstrated two separated clades in Equidae and the presence of a distant relationship between the domestic donkey breeds and Asian wild asses, indicating that domestic donkeys might not probably have originated from Asian wild asses. However, African wild asses were grouped as a sister to domestic donkeys. This study presented the complete mitochondrial genome of E. asinus, providing the important genetic background of protection and adequate utilization of domestic donkey breeds. [ABSTRACT FROM AUTHOR]