Resilience to bovine TB traced to key genes

Scientists have identified regions in the cow genetic makeup linked with resilience to tuberculosis disease. bTB bacteria modify gene activity in the cells’ chromosomes.

Researchers have mapped active and inactive genes in specialised lung immune cells, which play a key role in countering bovine tuberculosis (bTB) infections.

In order to infect cattle, bTB bacteria modify gene activity in the cells’ chromosomes – packages of genetic material – the scientists found.

Studies aiming to improve cattle genetics and resistance to bTB could benefit from these findings, led by scientists at University College Dublin (UCD) in collaboration with the Roslin Institute.

Genomic mapping

Key lung cells, called alveolar macrophages, are the first immune cells to encounter the bacteria that causes bovine TB during infection.

In order to map which genes in these cells are active or altered during infection, the team investigated all the chemical changes in the chromosomes of infected macrophages.

During infection, the bacteria modify gene activity in macrophages to facilitate their survival inside these cells.

Threat to animals and people

Bovine TB is caused by infection with Mycobacterium bovis, which can also cause disease in other mammals, including humans. Bovine TB is a threat to both livestock and people, causing up to US$3 billion loss to agriculture each year.

Our study will help to significantly narrow down the genomic regions of interest for breeding programmes to enhance the resilience of cattle to this important disease.

Bovine TB is a complex disease that is a threat to both livestock and humans and which has been difficult to control in many countries. We have used epigenomics to map regulatory elements in infected cells. Our findings highlight the importance of collaborating with international partners.