Genetic diversity and matrilineal genetic signature of native Ethiopian donkeys (Equus asinus) inferred from mitochondrial DNA sequence polymorphism

We investigated mitochondrial DNA (mtDNA) sequence polymorphism of six morphologically diverse domestic donkey (Equus asinus) populations in Ethiopia. These populations include: Abyssinian (AB), Afar (AF), Hararghe (HR), Ogaden (OG), Omo (OM) and Sinnar (SI). Genetic relationships and other diversity parameters were inferred from 39 randomly selected mtDNA D-loop partial sequences, characterized by 29 polymorphic sites defining 19 distinct haplotypes. Moreover, haplotype and nucleotide diversity in Ethiopian donkey populations were 0.903±0.032 and 0.020±0.003, respectively. A network analysis produced moderate star-like patterns suggesting past population demographic and spatial expansion. Population subdivision estimates demonstrated that Sinnar donkeys are considerably divergent from the other donkey populations. To trace the matrilineal genetic origin of Ethiopian donkeys, we retrieved 221 previously published domestic donkeys' mtDNA D-loop sequences from the GenBank (146 from Chinese and 75 from worldwide domestic donkeys). The haplogroup derived from the Ethiopian sources formed the center of the network from which most of the worldwide domestic donkey populations emerged. This suggests that Ethiopia could be one of the centers of diversities for domestic donkeys in the Horn of Africa. The present study also overrides some previous reports that claims donkeys were solely an Egyptian domesticate.