Great work by James Ward and supervisor David MacHugh on their paper in iScience on Genome-wide local ancestry and evidence for mitonuclear coadaptation in African hybrid cattle populations (Bos taurus/indicus)
The study used high density SNP date to assess whether ancestry at mitochondrially-targeted nuclear genes in African admixed cattle is impacted by mitonuclear functional interactions and their results support the hypothesis of incompatibility between the taurine mitochondrial genome and the zebu nuclear genome.
Study Highlights
- Using SNP data, we find evidence for mitonuclear coevolution in hybrid African cattle.
- Increased taurine ancestry at mitochondrially-targeted nuclear genes in several breeds.
- Observed for genes encoding proteins that interact with mtDNA-encoded proteins.
- Our results support the hypothesis of mitonuclear incompatibility in African cattle.
Study summary
The phenotypic diversity of African cattle reflects adaptation to a wide range of a groecological conditions, human-mediated selection preferences, and complex patterns of admixture between the humpless Bos taurus (taurine) and humped Bos indicus (zebu) subspecies, which diverged 150-500 thousand years ago. Despite extensive admixture, all African cattle possess taurine mitochondrial haplotypes, even populations with significant zebu biparental and male uniparental nuclear ancestry. This has been interpreted as the result of a human-mediated dispersal ultimately stemming from zebu bulls imported from South Asia during the last three millennia. Here we assess whether ancestry at mitochondrially-targeted nuclear genes in African admixed cattle is impacted by mitonuclear functional interactions. Using high-density SNP data, we find evidence for mitonuclear coevolution across hybrid African cattle populations with a significant increase of taurine ancestry at mitochondrially-targeted nuclear genes. Our results, therefore, support the hypothesis of incompatibility between the taurine mitochondrial genome and the zebu nuclear genome