Author
PORTO-NETO, LAERCIO - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
REVERTER, ANTHONY - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
PRAYAGA, KISHORE - Zoetis | |
CHAN, EVA K.F. - Garvan Institute Of Medical Research | |
JOHNSTON, DAVID - University Of New England | |
HAWKEN, RACHEL - Cobb-Vantress, Inc | |
FORDYCE, GEOFFREY - University Of Queensland | |
FERNANDO GARCIA, JOSE - Sao Paulo State University (UNESP) | |
Sonstegard, Tad | |
BOLORMAA, SUNDUIMIJID - Department Of Primary Industries | |
GODDARD, MIKE - Department Of Primary Industries | |
BURROW, HEATHER - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
HENSHALL, J.M. - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
LEHNART, SIGRID - Commonwealth Scientific And Industrial Research Organisation (CSIRO) | |
BARENDSE, WILLIAM - Commonwealth Scientific And Industrial Research Organisation (CSIRO) |
Submitted to: PLoS Genetics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/21/2014 Publication Date: 11/24/2014 Citation: Porto-Neto, L.R., Reverter, A., Prayaga, K.C., Chan, E., Johnston, D.J., Hawken, R.J., Fordyce, G., Fernando Garcia, J., Sonstegard, T.S., Bolormaa, S., Goddard, M., Burrow, H., Henshall, J., Lehnart, S., Barendse, W. 2014. The genetic architecture of climatic adaptation in tropical cattle. PLoS Genetics. 9(11):e113284. Interpretive Summary: Adaptation of global food systems to climate change is essential to feed the world in the future. One way to improve livestock production in developing countries is to combine heat and disease tolerance traits of adaptation to heat and tropical diseases typically found in zebu (humped cattle) with high productivity traits common to European-derived cattle breeds found in developed countries. In pursuit of this intuitive approach, Australian cattle producers have been developing composite breeds of cattle (indicine x taurine crossbreds) or selecting zebu breeds of cattle for higher production for decades under conditions of high heat, lack of water, poor quality feedstuffs, parasites, and tropical diseases. This study explored the genetic architecture for a subset of these cattle possessing varying degrees of zebu ancestry (nearly 5,000 animals) by measuring ten traits relevant to tropical cattle production and then using genome-wide association analysis to find genomic locations of the genes affecting these traits. The major findings were that nine of the ten traits are influenced by a few genes with major effects, and in one case a single gene accounted for more than 71% of the genetic variation. The other major finding was that a 20 million base-pair region of Chromosome 5 had effects on parasite resistance, yearling growth, body condition score, coat color and penile sheath score. Overall, these results point to several important genes that have large effects on adaptation that could be introduced into more temperate cattle without detrimental effects on productivity. The results of this study are a first step towards developing DNA tools to faciliatate selection for these traits. Technical Abstract: Adaptation of global food systems to climate change is essential to feed the world in the future. Tropical cattle production, an important mainstay of profitability for farmers in the developing world, is dominated by conditions of heat, lack of water, poor quality feedstuffs, parasites, and tropical diseases. Introducing more productive European cattle into these systems has been accompanied by significant stock loss, and the results of cross breeding of taurine x indicine cattle have been unpredictable due to the dilution of adaptation to heat and tropical diseases. In this study, we explored the genetic architecture of ten traits relevant to tropical cattle production using genome wide association studies of 4,662 animals of varying degree of indicine ancestry. We show that nine of the ten have genetic architectures that include genes of major effect, and in one case a single gene that accounted for more than 71% of the genetic variation. One genetic region in particular had effects on parasite resistance, yearling growth, body condition score, coat colour and penile sheath score. This region, extending for at least 20 Mb on BTA5, appeared to be under genetic selection possibly through maintenance of haplotypes by selection of breeders. We found that the amount of genetic variation and the genetic correlations between traits did not depend upon the degree of indicine content in the animals, although the percent of indicine content of an animal was correlated to its performance for most of these traits. Climate change is expected to expand some conditions of the tropics to more temperate environments, which may impact negatively on global livestock health and production. Our results point to several important genes that have large effects on adaptation that could be introduced into more temperate cattle without detrimental effects on productivity. |