27 October 2020
Tracing the ancestry of African cattle
Published online 29 September 2020
Study deepens understanding of the domestication and resilience of African cattle.
An ancient crossbreeding of Bos taurus (African taurine) with Bos indicus (Asian zebu or indicine) probably shaped the genome of today’s cattle in the Horn of Africa. The finding suggests that the combination of these two ancestries enabled African pastoralism to flourish.
An international team of scientists, including a researcher at the University of Khartoum, Sudan, analysed the genes of 172 indigenous African cattle from 16 breeds representing the main cattle groups and found the crossbreeding event likely occurred around 750 to 1,050 years ago.
Corresponding author, Olivier Hanotte, of the International Livestock Research Institute in Ethiopia, says, “The genetic makeup of present-day indigenous African cattle is not a random admixture of taurine and zebu. It has been selected to be optimal for the agro-ecologies in which the animals are found.”
For example, the team uncovered genes related to the immune response and to heat tolerance in cattle with predominantly indicine origins, and genes related to the inflammatory response in cattle with predominantly taurine origins. They further identified a taurine gene linked to parasitic tolerance in crossbreeds living in areas where the disease trypanosomosis is prevalent.
The study provides important context for informed crossbreeding and further blending of desirable traits. “Fortunately, we do not have to wait 1,000 years now to get the final product,” says Hanotte. “We have genetic marker-based selection tools and strategies, which allow us to achieve in a few generations what would have otherwise taken several hundred years of human selection. Genome editing approaches and new reproductive technologies may also help speed up the process.”
Kim, K. et al. The mosaic genome of indigenous African cattle as a unique genetic resource for African pastoralism. Nat. Genet. https://doi.org/10.1038/s41588-020-0694-2 (2020).