Genomic Landscape of the Mitochondrial Genome in the United Arab Emirates Native Population

Abstract

In order to assess the genomic landscape of the United Arab Emirates (UAE) mitogenome, we sequenced and analyzed the complete genomes of 232 Emirate females mitochondrial DNA (mtDNA) within and compared those to Africa. We investigated the prevalence of haplogroups, genetic variation, heteroplasmy, and demography among the UAE native population with diverse ethnicity and relatively high degree of consanguinity. We identified 968 mtDNA variants and high-resolution 15 haplogroups. Our results show that the UAE population received enough gene flow from Africa represented by the haplogroups L, U6, and M1, and that 16.8% of the population has an eastern provenance, depicted by the U haplogroup and the M Indian haplogroup (12%), whereas western Eurasian and Asian haplogroups (R, J, and K) represent 11 to 15%. Interestingly, we found an ancient migration present through the descendant of L (N1 and X) and other sub-haplogroups (L2a1d and L4) and (L3x1b), which is one of the oldest evolutionary histories outside of Africa. Our demographic analysis shows no population structure among populations, with low diversity and no population differentiation. In addition, we show that the transmission of mtDNA in the UAE population is under purifying selection with hints of diversifying selection on ATP8 gene. Last, our results show a population bottleneck, which coincides with the Western European contact (1400 ybp). Our study of the UAE mitogenomes suggest that several maternal lineage migratory episodes liking African–Asian corridors occurred since the first modern human emerges out of Africa.

Fine-Scale Genetic Structure in the United Arab Emirates Reflects Endogamous and Consanguineous Culture, Population History, and Geography

“…Additionally, we found in the Emirates the African A and B haplogroups and the predominantly South Asian haplogroups L1 and R2, mirroring admixture patterns we detected from genome-wide analysis. Similarly, we found African mitochondrial (mtDNA) haplogroup L in the Emirate with a frequency of $15%, almost twice as high as previously reported from the Emirates (Aljasmi et al 2020). Although the South Asian haplogroups U2-U4 were $8% in our data set.…”

Characterizing the diversity of MHC conserved extended haplotypes using families from the United Arab Emirates

“…Natural selection 3 , 8 , 17 is often considered an important component in the evolution of the MHC and the production of CEHs. However, evident by the information presented here and other reports 42 – 44 , it seems that the MHC genomic landscape of the contemporary UAE nationals must have also been shaped by both transcontinental migration between Africa, Asia, and Europe, which involved a diverse array of ethnic groupings 34 , 51 , and the nomadic lifestyles of some Arabian communities, notably the Bedouins.…”

“…Following that, a comprehensive, large-scale stratification study of the UAE population concluded that genetic admixture throughout the Arabian Peninsula's eastern shore and south-eastern tip happened gradually and without clear social stratification boundaries 43 . This, and another mitogenome study 44 , have shown that there was no apparent association between birthplace and ancestral background, indicating that the contemporary UAE population developed over generations prior to the establishment of the current political borders with a significant genetic influence from the Middle East, Central/South Asia, and Sub-Sahara 43 .…”

Heterogeneity in biomarkers, mitogenome and genetic disorders of Arab population with special emphasis on large-scale whole-exome sequencing

“…Since the earliest modern human emerged from Africa, multiple maternal lineage migratory events favoring African-Asian corridors have occurred, according to the research based on UAE mitogenomes [157]. Ancestral sharing with Africa, the Near East and East Asia was also revealed from the study [157].…”

“…The report from Emirati population showed that the Arab population received sufficient gene flow from African ancestries. Furthermore, the study showed that the Arab population received sufficient gene flow from Africa ancestries and a demographic bottleneck was observed that occurs around the time of Western European contact [157].…”