“It’s this really amazing natural phenomenon and we don’t know – or we didn’t know – much about how it came about or how evolution had changed it over time,” says Gregory Barsh at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama. “Why does the tiger have stripes and the cheetah have spots? How does evolution act on those on a common mechanism to give rise to different patterns?”
To learn more, Barsh and his colleagues examined fetal cat skin from embryos at different stages of development obtained from feral cat spay-and-neuter clinics.
They noticed that the embryonic skin was divided into alternating thick and thin regions, which they later discovered corresponded to hair follicles that produce different types of melanin.
Through analysing the gene expression of individual fetal cat skin cells at different levels of development, the team determined that embryonic differences in the expression of the gene DKK4 give rise to variations in the shape and colour of cat fur patterns. These findings may also apply to other mammals with patterned fur, says Barsh.
“Most of the coat colour discoveries in mammals are performed in mice, and mice don’t have spots and stripes. So, for several years now, we’ve been saying that domestic cats could be a good model,” says Eduardo Eizirik at the Pontifical Catholic University of Rio Grande do Sul in Brazil. “Just finding the gene by itself is a major contribution because we can now look at the gene in other species.”
“Domesticated cats have undergone selective breeding throughout many generations, so it remains to be seen whether the molecular processes uncovered here also explain natural variation in wild felid species,” says Ricardo Mallarino at Princeton University in New Jersey.
While it would theoretically be possible to use this gene to design cats with specific patterns, Barsh says he would discourage any efforts to do so, given the number of unwanted and feral cats already in existence. “I’m not very excited about promoting a mechanism to allow people to make designer cats if it comes at the expense of animal health,” he says.
Journal reference: Nature Communications, DOI: 10.1038/s41467-021-25348-2
Sign up to Wild Wild Life, a free monthly newsletter celebrating the diversity and science of animals, plants and Earth’s other weird and wonderful inhabitants