A recent study led by Christopher Kaelin and his colleagues has unveiled the genetic mutation responsible for the distinctive orange coloration in cats. This study was released online in the journal Current Biology. It’s a continuation of prior work that first mapped a small area of the X chromosome associated with this trait. Through extensive genetic analysis, the team has made significant strides in understanding the molecular identity of the sex-linked orange mutation.
The probe initially launched by focusing on the X chromosome. Through genetic analysis, researchers were able to identify 51 variants as being prevalent among male orange cats. They eliminated 48 of these variants from consideration since they appeared in some non-orange cats, narrowing their search for the specific mutation. We all know that a minor removal was found. This deletion increases the expression of the Arhgap36 gene, which is typically highly expressed in neuroendocrine tissues. Its overexpression can result in tumor formation, showing how complex this gene’s role is in feline genetics.
Kaelin’s research doesn’t stop with house cats. Beyond species like domestic cats and woodpeckers, he dives deep into the theory of colors and patterns to other animals, such as dogs, cheetahs, tigers, bears, zebras, and hamsters. This broader focus underscores a commitment to understanding how genetic variations contribute to the diverse appearances of animals across species. Since the beginning of the 20th century, the genetics of cat color and pattern has fascinated scientists. Lately, they’ve turned impressive focus and firepower to this truly exciting area.
Females cats with one copy of the sex-linked orange mutation have a unique appearance. This is why you often see a mottled pattern on these cats called tortoiseshell or calico. This strange phenomenon is an example of the complex interplay between genes and morphology in these animals.
Greg Barsh, MD, Ph.D., the senior author of the study and emeritus professor of genetics and pediatrics at Stanford, told me something very significant. This finding, he said, illustrates how genes evolve to acquire new functions, allowing populations to adjust. Kaelin followed this line of thought, arguing that the orange mutation is a perfect example of the turbulence of genetic evolution.
Ultimately, these discoveries open the genetic black box to explain what makes your favorite pooch look like the delightful mutt that he is. Along the way, they sharpen our view of how these mutations work to change color in diverse species. This is where researchers like Coon and others actively investigate these genetic variations. Their work opens the door to more informed advancements in veterinary genetics and animal breeding practices.