A global evaluation of mitochondrial DNA diversity and distribution of dromedary, Camelus dromedarius from north-central Saudi Arabia.

Knowledge of genetic variability within and among types and breeds of dromedary (Camelus dromedarius L.) can be a valuable asset in selective breeding of desirable characteristics and will shed light on their origin, dynamics of domestication, and dispersion. Variability in an 809 bp segment of the mtDNA genome was measured within and among dromedaries from eight indigenous and one exogenous breed from Ha'il in north-central Saudi Arabia. Sixteen mtDNA haplotypes were identified among 47 camels. Haplotypic diversity among breeds is high (H_d = 0.817); most of the AMOVA variance (55.05%) occurs within breeds. Phylogenetic comparison of these haplotypes with those obtained across their geographic range showed that most haplotypes were placed within the same cluster with ancient wild dromedaries and the two newly identified haplotypes in this study. The most prevalent haplotypes found in dromedaries from this area appear to be ancestral to most other dromedaries and differ from each other by only one SNP. These results support the hypothesis that the Arabian Peninsula is a hub of diversification for dromedaries.