Montague, MJ, Li G, Gandolfi B., et al. Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication. Proc Natl Acad Sci U.S.A. 2014 Dec 2;111(48):17230-17235. Partially funded by Winn Feline Foundation (W10-014, W09-009)
Evolution of domestic cats from ancestral wildcats occurred approximately 9,500 years ago coinciding with human transition toward a more agricultural lifestyle. By serving a beneficial role regarding vermin control during this transition period was likely the impetus that started selection of physical and behavioral traits leading to domestication.
A large international team led by researchers at The Genome Institute of Washington University in St. Louis, MO, used the female Abyssinian cat named Cinnamon, as a DNA source from which the first high-resolution (~ 14x) whole-genome reference was constructed. In order to identify genomic regions associated with the domestication process, they used whole-genome analyses of cats from different domestic breeds and wildcats using data pooling methods. Compared with wildcat genomes, domestic cat genomes showed evidence of recent selection in genes linked to memory, fear-conditioning, and stimulus-reward learning; all related to the evolution of tameness. For example, domesticated cats would have needed to become less fearful of humans and develop a working memory in order to adapt to new habitats. The researchers also identified gene-coding proteins that affected their sensory processes, especially affecting vision (e.g., improved vision for hunting rodents during dusk and dawn) and hearing (e.g., increased hearing range in order to hear ultrasounds emitted by their prey). In addition, the domestic cat genome was compared to other mammals – human, tiger, dog, and cow. From these comparisons, positively selected genes involved in lipid (i.e., fat) metabolism are thought to underlie cats becoming obligate carnivores. In the diet of carnivores, fat typically provides most of the fuel for energy; thus, cats need genes coding for proteins that breaking down fats efficiently; the team found such lipid-metabolizing genes that do just that.
From all the genomic insights deemed from this study, it is suggested that the major force that altered the first domesticated cat genome toward domestication was becoming accustomed to humans for food awards. [GO]