Scientists Create TB-Resistant Cows in China

With badger-cull conflict having swept the UK for the past couple of years, doesn't it make you wonder how much easier everything would have been if Bovine TB weren't something to worry about? Well, thanks to scientists from the Ministry of Agriculture in Northwest A&F University in China, that might very well be something we can look forward to in the near future. Researchers have managed to genetically engineer a herd of cattle that are less likely to contract the disease, and even if they do fall ill, their symptoms aren't as bad. You can check out the study, published in PNAS . Bovine TB (tuberculosis) is a risk to cattle all over the world, and other animals that can carry the disease, such as badgers and deer - even cats and dogs. The long-term goal of carrying out a project such as this one is to avoid the need to cull animals susceptible to the disease by breeding tuberculosis-resistant cattle. Prevention is better than a cure and all that. Using hi-tech genetic technology, the study authors inserted in the mouse gene SP110 into fetal Holstein-Friesian fetal cells. This gene was chosen because it is known for its innate immunity properties against tuberculosis. In mammals, the gene can control the growth of the bacterium and triggers the infected cells to undergo programmed cell death, rather than have the cells depleted by the disease. The fetal cow cells were then used as nuclear donors for cow embryos, which led to 13 live cattle. The cows were tested both in the lab, being directly infected with Bovine TB and on the farm, being kept in the same pen as other animals with the disease. Instead of just developing the condition as so many cows have in the past, these cows were shown to have immune cells that are better at slowing the growth of TB-causing bacteria. The bacteria grew at around half the rate it did in cows without the added gene. This led to a third of the new cows either not catching TB at all or displaying far lesser symptoms than their brothers and sisters without the added gene. And all of the benefits of SP110 were even passed down to the next generation. This means that if this method of adding an extra gene to cows is used in the future, there will be no need to develop new treatments for the offspring of TB-resistant cattle. Experts on animal genetics have commented on the study explaining how great a step forward this work is towards creating disease-resistant animals. However, they do agree that it is still yet to be determined if this approach will be able to protect cows against TB when exposed to high doses of the pathogen. But... "Our results contribute to the control and prevention of bovine tuberculosis," the study authors said, "and provide previously unidentified insight into breeding animals for disease resistance."