March 2, 2015

expert reaction to genetically engineered cows resistant to bovine TB

Writing in the journal PNAS, a group has reported the generation of a genetically modified breed of cattle which are more resistant to tuberculosis than their unmodified counterparts, a trait which could be passed onto subsequent generations.

Prof. Bruce Whitelaw, Professor of Animal Biotechnology at the Roslin Institute, University of Edinburgh, said:

“The world faces unprecedented population growth on the backdrop of competing pressure on agricultural land and resources. Food security for all is an international imperative. Society needs to embrace many strategies to address this global challenge – both traditional and new – with many seeing genetic engineering as contributing to the much needed solutions.

“The paper by Haibo Wu and colleagues promotes optimism in this regard. These authors describe genetically engineered cattle with reduced disease severity upon pathogen challenge both in the lab and, importantly, in the engineered animals themselves. Their target disease is bovine TB, a disease endemic to many countries of the world, with the common approach of identifying infected cattle for culling. In addition, in the UK there has been the controversial policy of culling badgers – this is the setting for discussion on the benefits of cattle with enhanced resilience to bovine TB.”

Prof. Heiner Niemann, Head of the Institute of Farm Animal Genetics at Friedrich-Loeffler-Institut, Germany, said:

“This is an interesting novel approach to create animals with enhanced disease resistance.  Using new genomic tools that allow us to induce targeted genetic modifications (TALEN) the authors created first a genetic deletion and inserted a new genetic element known to be involved in controlling Mycobacterium tuberculosis infections (SP110). The new gene changed important biochemical pathways active after M. tuberculosis infection towards apoptosis and avoided/reduced the devastating necrosis pathway usually associated with M. tuberculosis infections. Challenge experiments revealed that the animals were protected against M.tuberculosis at least at rather low doses.

“These findings are another step towards the creation of disease resistant livestock animals based on advanced genetic tools. Whether this approach protects cows against TB infection  when exposed to high doses of the pathogen remains to be determined.

“The present results would not yet support a decision to stop targeting badgers as the main vector of the pathogen. Nevertheless, results pave the way towards developing new strategies for breeding disease resistant farm animals, thereby avoiding in the future mass culling of afflicted farm animals and detrimental economical effects on animal production.”

‘TALE nickase-mediated SP110 knockin endows cattle with increased resistance to tuberculosis’ by Haibo Wu et al. published in PNAS on Monday 2 March 2015. 

Declared interests

None declared