Bengal cat coats are less wild than they look, genetic study finds

“The big-picture question is how genetic variation leads to variation in appearance,” Barsh said.
“This is a question that has all kinds of implications for different species, but we think that cats offer an especially tractable way to study it.”

From the 1960s through the 1980s, breeders, led by biologist Jean Mills, crossed the wild Asian leopard cat species Prionailurus bengalensis with domestic cats to create a new, visually striking cat breed. Over many generations, the cats with the desired physical characteristics and temperaments were progressively selected and bred. By 1986, the Bengal cat was recognized as its own new breed by the International Cat Association.

Barsh and Kaelin saw Bengals — with their recent genetic origin and unique appearance — as a particularly interesting way to study how genetic variation causes diversity in form, color and pattern. In 2008, they began reaching out to cat breeders, attending cat shows, and collecting cheek swabs and photographs of Bengal cats.

Genetic surprises

The Stanford Medicine team suspected that Bengal cats might give them an accessible way to probe the genetics of wild cat colors and patterns that had evolved naturally. But after sequencing 947 Bengal cat genomes, they found something surprising: There were no parts of the wild Asian leopard cat genomes that were found in all Bengal cats.

“Nearly every Bengal cat breeder and owner has this idea that the distinctive look of the domestic Bengal cat must have come from leopard cats,” Barsh said. “Our work suggests that’s not the case.”

Instead, the genetic signatures suggested that the unique appearance of Bengals was a result of variations in genes that had already been present in domestic cats.

The team found something similar when they looked specifically at “glitter”: About 60% of all Bengal cats have particularly soft, iridescent fur that glitters like gold in the sunlight. A mutation in the gene Fgfr2, they showed, is responsible for glitter and comes not from leopard cats but from domestic cats. Glitter and the underlying Fgfr2 mutation are nearly specific to Bengal cats. Interestingly, the mutation reduces the activity of the protein encoded by Fgfr2, rather than rendering it inactive as many mutations do. This sheds light on how variations in genes can cause subtle changes in appearance, the researchers said.