Researchers at the University of Georgia (UGA) have identified the DNA variants responsible for determining the length of dogs' ears. The study, published in Scientific Reports, analyzed the genetic code of over 3,000 dogs, wolves, and coyotes.
The research found that ear length is influenced by genomic differences near the gene MSRB3. This gene was previously known to differentiate between dogs with pointy (prick) ears, like German shepherds, and droopy (drop) ears, like bloodhounds. Mutations in MSRB3 are also linked to hearing loss in humans.
Leigh Anne Clark, corresponding author and an associate professor at the UGA College of Veterinary Medicine, stated that the study, which focused exclusively on drop-eared dogs, revealed an additional allele on top of the known MSRB3 gene combination. This extra allele dictates whether a drop ear will be short or long.
Dog ears exhibit various shapes and sizes, including prick, drop, button, rose, and bat ears. These characteristics have evolved naturally and have also been amplified through selective breeding by humans, influencing both form and function.
Clark's lab typically investigates inherited diseases in dogs. She emphasized that understanding the genes and genomic regions selected for in breeds is crucial when studying genetic disorders. This new insight into the genetic basis of ear size can inform future research into mapping other diseases.
Identifying alleles that underlie disease enables the development of genetic tests for breeders, which can help reduce the frequency of harmful alleles in dog populations and ultimately aim to decrease or eliminate disease incidence.