Sheep genome experiments conducted in campus
Sheep with abnormally long legs, sheep with exceedingly large buttocks and sheep with a high resistance to fatal parasites: All are being studied on Utah State University campus.
Noelle Cockett, professor of animal, dairy and veterinary sciences department, is the national coordinator for the U.S. genome sheep projects and has been at the head of many scientific breakthroughs relating to the DNA of sheep.
“Our lab is looking at different traits in sheep that are either favorable or unfavorable,” Cockett said.
Most recently, Cockett has been working with Sandy Eng, a senior majoring in biology, Louisiana State University and the University of Georgia to pinpoint the DNA differences in sheep which make some very resistant to parasites while others are very susceptible.
Gulf Coast Native (GCN) sheep appear to be resistant to internal parasites such as Haemonchus contortus which can be fatal to the animals, while other sheep- such as the Suffolk-are very vulnerable to the parasites. The focus of the research has been to identify the genetic differences between the GCN and Suffolk sheep that may play a part in the resistance differences.
Cockett’s Molecular Genetics Lab has been, since the summer, testing blood samples of the different sheep and looking for genetic markers which could be associated with parasite resistance, Eng said. They have also tested the blood samples of the offspring of a GCN and Suffolk to statistically analyze the chances of resistance, or susceptibility and the possible genetic reasons.
“If you could identify why they’re resistant, you could find the right combination to breed,” Cockett said.
So far, Eng and Cockett’s work on the project has found genetic markers on two chromosomes most likely associated with parasite resistance and there is hope for further discoveries.
“We are hoping to find a marker that is strongly associated with parasite resistance with the continued research sheep could be specifically bred with the right partner to ensure that that offspring have a high resistance to parasites in the future,” Eng said.
Cockett has also studied Spider Lamb Syndrome in sheep which causes sheep affected with the disorder to have abnormally long and sometimes twisted legs, a curved spine, deformed ribs and a lack of body fat. Cockett discovered in 1998 and 1999 that the defective gene which causes Spider Lamb Syndrome is the same protein in humans that causes dwarfism. However, the protein, FGFR3, instead of stopping bone growth prematurely as it does in cases of dwarfism, doesn’t shut down bone growth when it should with Spider Lamb Syndrome, causing the lamb’s bones to grow unusually long. Cockett now has a commercial company which tested more than 8,000 sheep blood samples as possible carriers of the defect.
Cockett’s research has also identified genetic markers which cause the condition Callipyge which produces sheep to have unnaturally large buttocks. Unlike Spider Lamb Syndrome and parasites, Callipyge is a favorable trait because it produces more meat, therefore those who raise sheep would want to breed sheep that, because of their DNA, produce Callipyge sheep.
Cockett and Eng are both very pleased with how the sheep genome research has gone.
“I have really enjoyed my experience in the lab because the work environment is great. I have been able to perform experiments that I have learned in class and it has helped me through some of my classes because I have had on-hands experience,” Eng said.
Cockett said, “There’s not all that many people in the world who work on sheep. Worldwide our lab is actually known for our work with genetic markers and sheep.”