Human Genomes Are Surprisingly Cat-Like
Cat genomes are more similar to ours than those of mice and dogs, yet researchers say felines are underutilized in genetic studies of disease
Cats have genomes that are structured in much the same way that humans’ are, and an article published this week in the journal Trends in Genetics argues this unique quality has been underutilized by scientists who have more commonly studied mice and dogs, reports Katherine J. Wu for the Atlantic.
“Other than primates, the cat-human comparison is one of the closest you can get,” in terms of genome organization, study author Leslie Lyons, a veterinarian specializing in cat genetics at the University of Missouri, tells the Atlantic.
And yet, Lyons adds, “cats are often underappreciated by the scientific community.”
Dogs and mice, by contrast, have chromosomes that have been reshuffled over their respective evolutionary histories, making them more complicated to use as genetic analogues for our species.
Cats’ genomic similarity makes them more straightforward models for studying human diseases. It could also scientists understand the genetic dark matter of our genomes—that is, non-coding DNA that doesn’t provide instructions for making proteins yet still comprises some 95 percent of the human genome.
"As we discover that perhaps animals have more similar spacing between genes and the genes are in the same order, maybe that will help us to decipher what's going on with humans," Lyons says in a statement. "Working with a primate is on the expensive side, but a cat's affordability and docile nature make them one of the most feasible animals to work with to understand the human genome."
Lyons and her collaborators have also recently published the most detailed cat genome ever sequenced, reports James Gorman for the New York Times. This new genome is even more detailed than the most exhaustively sequenced dog genome.
“The goal is to have the complete encyclopedia of the cat’s DNA, so we can actually fully understand the genetic basis for all traits in the cat,” William Murphy, a geneticist at Texas A&M University and Lyons’ frequent collaborator, tells the Times.
An improved genetic understanding of cats could usher in the development of precision medicine for genetic diseases in cats, which could one day turn into gene therapy for humans. For example, Lyons writes that the genetic illness polycystic kidney disease is prevalent in some cat breeds, and that the condition also occurs in humans. So, if researchers can find the right genetic treatment to address the disease in cats, it might offer clues for developing a treatment in our species as well.
Per the Atlantic, cats are unlikely to replace mice, which are cheaper to breed and house, as the go-to lab mammal. But as Gita Gnanadesikan, a canine researcher at the University of Arizona, tells the Atlantic, the choice of which animals’ genes are worth studying doesn’t have to be either or. “In genetics, there’s this tension: Do you try to learn everything you can about a small number of organisms, or do you branch out and try to learn little bits about a larger number of species?” Gnanadesikan tells the Atlantic. “I think one of the answers to that is just … yes.”