signatures of selection on dromedary genome
Dromedary camels are domestic species characterized with various adaptive traits associated with their environmental conditions. The genome of this well-adapted species was manly investigated for genetic diversity with minimal efforts to determine the genetic regions and haplotypes under selection. Such elements are considered as valuable sources to be conserved to maintain dromedaries' adaptabilities. Here, we have analyzed the whole genome sequence of 40 dromedary camel samples from different populations covering the different geographical locations on the Arabian Peninsula. De-correlated composite of multiple signals (DCMS) approach was used to detect candidate regions with signatures of selection upon combining four intra-population analyses (Tajima's D index, nucleotide diversity (pi), integrated haplotype score (iHS), and number of segregating sites by length (nSL)). A total of 36 candidate regions harboring 87 genes were defined to be under positive selection. These regions overlap with 185 haplotype blocks encompassing 1340 haplotypes, in which 30 (~2%) are considered as fixed haplotypes with frequency = 0.9. The defined candidate genes are associated with different biological process related to adaptive physiology of dromedaries; neurological pathways and brain development, musculoskeletal development and interaction, fertility, fat distribution and energy expenditure, immunity, visual development, and kidney physiology. The outputs of this study will pave the way for further investigations at the whole genome level to further understand the evolutionary pressures shaping the dromedary genome. Such patterns will help in developing the breeding system of dromedaries to conserve these genetic elements and improve their productivity.