A genomic analysis has been conducted to explore the origin of a short-tailed trait found in some Tsushima leopard cats, an endangered species that lives only on Tsushima Island in Japan. During a field survey, researchers from Kyoto University discovered three Tsushima leopard cats with shortened tails, a feature more commonly seen in domestic cats. One of these animals had a tail that was only half the normal length, leading the team to investigate whether this unusual trait was due to recent interbreeding with domestic cats or a natural variation within the leopard cat population. To understand the genetic background of this trait, the researchers analyzed the full genome of the short-tailed Tsushima leopard cat. They compared this data with genome information from 15 other Tsushima leopard cats, five domestic cats found on the island, and four Amur leopard cats from the mainland. Using advanced genetic analysis techniques such as principal component analysis, genome-wide inbreeding estimates, mitochondrial DNA phylogeny, and other statistical methods, the team examined ancestry and potential genetic mixing. They also looked at two genes known to be involved in tail abnormalities in domestic cats. The results of the study, published in the journal Global Ecology and Conservation, found no evidence that the short-tailed Tsushima leopard cat had interbred with domestic cats. Every step of the whole-genome analysis confirmed that the short-tailed cat was genetically part of the Tsushima leopard cat population and showed no genetic abnormalities. However, the cause of the short tail remains unknown, leaving researchers puzzled about how this rare trait arose. The team observed short-tailed Tsushima leopard cats in different areas, suggesting that this unusual feature may be more widespread than previously thought. In the future, the researchers plan to study more short-tailed individuals and are working on noninvasive genetic monitoring techniques that could help track the cats without capturing them. This study marks the first time a short-tailed individual has been clinically and genomically characterized in the wild cat genus Prionailurus, offering new insights into the genetics of this rare and endangered species.