Title: Evidence of common signatures of selection in the genomes of West African cattle and the Yoruba human population Authors
Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2014
Publication Date: April 23, 2014
Citation: Utsunomiya, Y.T., Sonstegard, T.S., Hanotte, O., Van Tassell, C.P., Garcia, J.F. 2014. Evidence of common signatures of selection in the genomes of West African cattle and the Yoruba human population. BARC Poster Day, Poster 66, pp.78. Technical Abstract: In 1954, Allison found that the sickle-cell anemia mutation in the beta hemoglobin gene was highly prevalent in West African people because it is protective against malaria, so carriers would thrive and leave offspring in spite of the genetic disease. This is one of the earliest evidences of an environmental selective pressure acting as a strong driver of recent human adaptation and evolution, and certainly the first documentation of natural selection leaving behind a traceable molecular signature. West African people have largely shared the same environments with indigenous cattle, and therefore it is possible that common selective pressures have shaped the genome diversity of both species. Moreover, these breeds show a remarkable resilience to hematozoon challenges, such as trypanosome-derived anemia. Here, we report the curious case of shared candidate signatures of selection in the genomes of West African taurine cattle (WAT) and the South Nigerian Yoruba human population in Ibadan. We used a panel of 722,155 single nucleotide polymorphism (SNP) markers to scan the genomes of indigenous WAT breeds for footprints of selection, and contrasted these data with European taurine, Southern Asian-descent indicine, and Eastern African indicine breeds. We applied a method based on composite statistics, namely meta-SS, to combine the results of genome-wide scans for selective sweeps obtained from three different methods (iHS, Rsb and FLK). In the human counterpart, we analyzed the HapMap3 data, which included 961,388 SNPs and European, West African and Asian samples. Comparative analysis of detected regions in both species point to several orthologous genes underlying adaptation to endemic disease; and in one specific case, a suggestive signature in cattle was found nearby the beta hemoglobin gene corresponding to a human signature implicated in resistance to malaria. Our study provides unique evidence for a common adaptive response in the genomes of West African cattle and the Yoruba population. Combinations of agnostic analyses and in-depth hypothesis-driven investigations should aid with validation to these findings and elucidate the driving forces that have shaped these exquisite patterns of genetic variation across species.