Welcome To The Dark Matter Digital Network

Scientists Discover Genes That Helped Turn Fearsome Wildcats Into House Cats

Cats are different than other domesticated animals. Unlike other species tamed for either food or labor, cats specialized in becoming mooches. Sure they catch mice, but it’s not like they do it for our sake. Despite these differences, many scientists believe that cats, like all domesticated animals, inherited certain genetic mutations from ancestors who were unafraid of humans. A new study identifies some of the genes that may be responsible for the differences between house cats and their wild ancestors. The research, published today in the Proceedings of the National Academy of Sciences (paywall), follows closely on the complete annotation of the cat genome, released in the journal Gigascience this August. Both were the result of a huge international effort, involving nearly a dozen research institutions. The scientists weren’t just trying to find out why kitties like us. The complete cat genome could improve understanding, and treatment, of the more than 250 diseases that afflict humans and cats in similar ways. House cats aren’t all that different from modern wildcats, the wild species most closely related to them. Wildcats have slightly larger brains, but in skeletal terms the two are nearly identical. (Most of the garish indoor cat breeds—from white-booted Birmans to long-coated Maine Coons, didn’t exist before 200 years ago.) The biggest difference is in their personalities, which starts in the genes, says Stephen O’Brien, one of the paper’s senior authors and chief scientific officer at the Theodosius Dobzhansky Center for Genome Bioinformatics in St. Petersburg, Russia. He says that cat domestication started about 10,000 years ago, with the spread of agriculture. Humans were creating sizable amounts of food waste, which attracted scavengers like wildcats. Some, says O’Brien, were genetically inclined to be friendlier, or at least less fearful, towards humans. Maybe they began to let our curious ancestors approach them as they were picking scraps of meat out of the bone pile, or perhaps a proto-kitteh even came in for a nuzzle. By comparing the wildcat and house cat genomes, and looking for places where the house cat genome had undergone rapid changes, the researchers found three possible genetic links to that change in temperament. Compared to wildcats, house cats have more mutations on genes known to mediate aggressive behavior, form memories, and control the ability to learn from either fear or reward based stimuli. Cats with these traits would have mated with each other, repeatedly passing them along from parent to kitten until a significant population became distinct from their still-aggressive cousins. “There’s a big difference between house cats and wildcats,” said Stephen O’Brien. “A house cat will sit on your lap, but a wild cat will hand you your behind.” These genes were most active in the neural crest, a group of embryonic cells that become the spinal cord in adult vertebrates. via WIRED.

Leave a comment