The genetic origins of the split tail seen in the twin-tail goldfish trace back to a mutation that emerged after approximately 600 years of domestication. This finding is reported in a study published this week in Nature Communications.
The twin-tail goldfish is a popular ornamental fish with a split tail that gives it a winged appearance. Goldfish domestication started at around 1000 AD in the Song dynasty of China, and the first records of the twin-tail variety date to about 600 years later. Twin-tails show a drastic modification of the tail skeleton resulting from artificial selection during domestication; these elaborate tails are very rare in nature.
Kinya Ota and colleagues identify a single mutation in one of two recently duplicated chordin genes. This mutation affects the caudal skeleton (the tail region) and fins during embryonic development causing the elaborate tail. This study sheds light on the genetic and developmental mechanisms of a fancy trait resulting from human-induced selection during domestication for ornamental proposes.