Researchers at University of Edinburgh's Roslin Institute have identified genes in cattle that could allow genetic selection for resistance to bovine tuberculosis (bTB). Their paper, titled “Genome-wide association study identifies novel loci associated with resistance to bovine tuberculosis,” is published in the journal Heredity.

The authors note that Bovine TB, caused by Mycobacterium bovis, is a chronic respiratory disease with substantial animal health and welfare consequences, and serious economic impact. In the Great Britain, Northern Ireland and Republic of Ireland, the disease accounted for £227 million in costs during 2010 and 2011. On a global scale, the zoonotic pathogen is estimated to cause 10 to 15 percent of human TB cases in the developing world and is considered to be the fourth most significant livestock disease in terms of impact on human health and economics in developing countries.

The study, which built on previous findings at the institute that indicated genetic variation in the degree of resistance to TB among cattle, compared the genetic codes of TB-infected cattle with those of uninfected animals.

The researchers genotyped study cattle using the Illumina BovineHD 700K BeadChip. They identified two novel resistance loci, designated PTRRT and MYO3B. They estimate that 21 percent of the phenotypic variance in TB resistance could be explained by all of the informative single-nucleotide polymorphisms, of which the region encompassing the PTPRT gene accounted for 6.2 percent of the variance and a further 3.6 percent was associated with a putative copy number variant in MYO3B.

“The results from this study add to our understanding of variation in host control of infection and suggest that genetic marker-based selection for resistance to bTB has the potential to make a significant contribution to bTB control,” the researchers concluded.

Read the full report in Heredity.