A genetic basis for short tails in Japanese Bobtail and Chinese short-tailed feral cats is identified in a study published in Scientific Reports this week. The research suggests that a mutation in the gene HES7 is responsible for the trait in these breeds.
Previous research has identified that the short tailed/tailless trait in the Manx and several bobtail cat breeds is due to a mutation in the T-box gene. However, it has been shown that this gene is not associated with the short-tailed trait in the Japanese Bobtail, indicating that at least one additional gene is involved in determining tail length in domestic cat breeds.
Shu-Jin Luo and colleagues conducted a genetic analysis of 13 cats from two generations and screened an additional 233 unrelated cats (including 126 feral cats from Asia and 107 breed cats) for genetic variations linked to tail length. The authors found that cats with one copy of the HES7 gene, with a mutation in which the amino acid valine is replaced with alanine, exhibited shortened tails to varying degrees. This ranged from a slight shortening (where the tail was approximately 25cm long), to tails between 10-20cm long. They also found that approximately one-third of the short-tailed cats from China examined did not carry the genetic variations in HES7 or T-box associated with short tails, which may suggest the existence of additional genes that contribute to short tails in these breeds of cat.