Homogeneity of Arabian Peninsula dromedary camel populations with signals of geographic distinction based on whole genome sequence data

Abstract

Dromedary camels in the Arabian Peninsula distribute along different geographical and ecological locations, e.g. desert, mountains and coasts. Here, we are aiming to explore the whole genome sequence data of ten dromedary populations from the Arabian Peninsula to assess their genetic structure, admixture levels, diversity and similarity indices. Upon including reference dromedary and Bactrian camel populations from Iran and Kazakhstan, we characterise inter-species and geographic genetic distinction between the dromedary and the Bactrian camels. Individual-based alpha genetic diversity profiles are found to be generally higher in Bactrian camels than dromedary populations, with the exception of five autosomes (NC_044525.1, NC_044534.1, NC_044540.1, NC_044542.1, NC_044544.1) at diversity orders (q ≥ 2). The Arabian Peninsula camels are generally homogenous, with a small degree of genetic distinction correlating with three geographic groups: North, Central and West; Southwest; and Southeast of the Arabian Peninsula. No significant variation in diversity or similarity indices are observed among the different Arabian Peninsula dromedary populations. This study contributes to our understanding of the genetic diversity of Arabian Peninsula dromedary camels. It will help conserve the genetic stock of this species and support the design of breeding programmes for genetic improvement of favorable traits.

Figure 1

Principle component analysis (PCA) plots on (a) dromedary and Bactrian camels and (b) dromedary camels from the Arabian Peninsula.

Figure 2

Admixture analysis plots of (a) K = 2 on the dromedary and Bactrian camels (dataset 1) and (b) K = 2 and 3 on the dromedary camels from the Arabian Peninsula (dataset 2). Hur Hurra, Mgh Magaheem, Shl Shual, Sfr Sofor, Wdh Wodeh, Sah Sahlia, Had Hadana, Awd Awadi, Awk Awarik, Omn Omani, Irn_drom Dromedary from Iran, Irn_Bac Bactrian from Iran, Kaz Bactrian from Kazakhastan.

Figure 3

Mean autosomal alpha diversity at the diversity orders q = 0 to 4. Populations: (1) Arabian Peninsula dromedary camels; (2) dromedary camels from Iran; (3) Bactrian camels from Iran; and (4) Bactrian camels from Kazakhstan. Mann–Whitney U test P-values for pairwise comparisons of dromedary (1 and 2) against Bactrian (3 and 4) are reported.

Figure 4

Average autosomal beta diversity at diversity orders q = 1 to 4. Populations: (1) Arabian Peninsula dromedary camels; (2) dromedary camels from Iran; (3) Bactrian camels from Iran; and (4) Bactrian camels from Kazakhstan.

Figure 5

Average autosomal similarity indices at diversity orders q = 1–4. Populations: (1) Arabian Peninsula dromedary camels; (2) dromedary camels from Iran; (3) Bactrian camels from Iran; and (4) Bactrian camels from Kazakhstan.