Friday, August 18, 2006
Researchers at Uppsala University, Sweden, have uncovered a genetic reason why newborn piglets are less tolerant to cold than other newborn mammals. It turns out that the gene that codes for the protein UCP1 was inactivated some 20 million years ago in the evolutionary line that pigs belong to. These findings, available here, are presented in the latest issue of the scientific journal PloS Genetics.
Brown fat plays an important role in newborn mammals, including our own children, since this tissue helps the newborn to maintain its body temperature by burning fat, which converts into heat. The protein UCP1 (Uncoupling Protein 1) has a key role in this energy conversion, which takes place in the cell mitochondria.
Piglets are sensitive to cold and shudder in order to maintain their body heat. No brown fat or UCP1 protein has previously been found in domesticated pigs. In a new study, Frida Berg and her colleagues have been able to show that the UCP1 gene was shut down about 20 million years ago in an ancestor of the wild boar. [evolution]