Fighting sheep worms with genomics

Leading-edge technology is being used by two CSIRO Livestock Industries' research teams to identify genes that enable sheep to resist intestinal parasites.

The discovery of such genes could lead to new products, control strategies, and markers to identify superior animals in selective breeding programs, which will substantially improve the overall health and welfare of the national flock.

With support from Meat and Livestock Australia (MLA) and Australian Wool Innovation (AWI) through their joint $30m Sheep Genomics Program, the Brisbane and Armidale-based teams will use modern genetic technologies - such as microarrays and the real-time polymerase chain reaction (PCR) - to determine the expression level of genes in worm-resistant and susceptible sheep.

"CSIRO Livestock Industries in Armidale has a long history of research into resistance to nematodes (worms), and has selectively bred nematode-resistant flocks of sheep that facilitate both projects," says Brisbane team leader, Dr Aaron Ingham.

"The Brisbane and Armidale teams will work closely together to conduct detailed complementary molecular genetic analyses on sheep produced from these flocks. The Armidale team will also provide the necessary parasitological and immunological expertise for both projects," he says.

The Brisbane team will use real time PCR to screen a number of 'candidate' genes that are known to be involved in disease responsiveness and resistance, tissue regeneration, wound repair, appetite and basic physiology.

The Armidale team will use microarray technology to undertake a broad, unbiased screen of thousands of genes, to identify those responsible for nematode resistance.

Gene expression that is consistently different between resistant and susceptible animals will be targeted for further study.