What makes Maine coons cuddly and Russian shorthairs standoffish? The answer may lie in the first sequence of the cat genome, published today. In all, geneticists have turned up 20,285 genes, the analysis of which could shed light on everything from human diseases to the underpinnings of feline domestication. The latest sequence comes courtesy of a 4-year-old Abyssinian cat named Cinnamon. The analysis is only a first pass and so is not as complete as that done for humans or dogs. Still, evolutionary biologist Stephen O’Brien and bioinformaticist Joan Pontius of the National Cancer Institute in Frederick, Maryland, and their colleagues were able to decipher about 65% of the gene-containing parts of the genome, or more than 20,000 genes. That’s perhaps 95% of the total, based on comparisons with other genomes.
Based on the structure of the chromosomes, the cat genome much more closely resembles that of humans than that of other nonprimate species. Unlike cats and humans, pieces of chromosomes in “the dog, mouse, rat, and others have been reshuffled like a poker deck,” says O’Brien. This conservation suggests that the cat’s genome has more in common with the ancient ancestor of cats, humans, and other mammals than, say, the dog’s does. Other surprises included an excessive amount of mitochondrial DNA stuck into the cat genome, although researchers have yet to figure out the reason or significance.