Genotyping of mitochondrial D-loop sequences in three breeds of sheep

Abstract

The geographical center of species diversity for sheep (Ovis aries) lies around several regions of Iraq and Iran. Therefore, it is necessary to explore the genetic relationships among these domesticated breeds and their maternal ancestors. This study was conducted to assess the mitochondrial D-loop genetic diversity in three breeds of Iraqi/Iranian prolific sheep, exhibiting clear differences in their geographical distributions and phenotypic traits. Five different SSCP-banding patterns were identified in Arabi, while only four distinct patterns were observed in both Karakul and Awassi sheep. One haplotype each in Karakul and Awassi was shared with Arabi. Sequencing reactions confirmed these patterns and validated the presence of 11 haplotypes and 16 variations distributed among studied populations. Arabi exhibited the maximum haplotype diversity, while Awassi exhibited the highest diversity of nucleotide polymorphism. The fixation index among populations showed a high sharing of genetic material among the investigated populations. The observed similar haplotypes showed the highest proportions in Arabi and Karakul and near the highest proportions in Awassi. In conclusion, higher nucleic acid variations were observed in the investigated Arabi and Awassi breeds than in the Karakul breed, signifying a potential role for D-loop-based genotyping in these differences in the three investigated ovine breeds.