Through constructing a phylogenetic tree among goats, cattle, horses, dogs, opossums and humans, researchers found the goat shared a common ancestor with cattle about 23 million years ago. Further comparison analysis revealed 44 rapidly evolving genes under positive selection, seven of which are immune-related genes and three are pituitary hormone or related genes. The immune-related genes identified also exist in cattle. The findings suggest that the rapid evolution of pituitary hormones may be related to the different features between goat and cattle in milk production, development rates of the fetus and/or hair variation.
The major histocompatibility complex (MHC) plays an important role in the immune system. In this study, the goat MHC was found to be located on chromosome 23 and contains two regions with length of 2.25 Mb and 360 kb, respectively. With the high quality genome assembly, further understanding of the goat MHC will be useful for immunological studies and vaccine development.
One of the distinguishing characteristics of mammals is the protective growth known as hair. It is produced by hair follicles within the skin, which could provide either protection (guard hairs) or insulation (underfur). The two major hair follicles include the primary hair follicle that produces only coat hair in all mammals, and the secondary hair follicle that can produce the cashmere or "fine hair" in certain mammals, including goats and antelopes. Despite a 2,500-year history and the extent of raw cashmere production, people are lack of understanding of the molecular mechanisms of cashmere formation and development.<
|Contact: Jia Liu|