In the fish identified two unique genes that could play a major role in the evolution of fins into limbs.
Removal of genes from the zebra danio embryos led to the loss aktinotrihii – horny filaments in fins, though protoplavniki turned into a kind of simple processes that paleontologists have found fossil, moving along the evolutionary path of quadruped animals.
In the early stages of embryonic development fins and limbs look equally daunting. In the future, but for future fish begin to form horny filaments, which become the basis for the fin rays. Employees of the University of Ottawa (Canada) Jing Zhang, and Marie-Andre Akimenko drew attention to the fact that genes aktinodin-1 and 2 are particularly active during the development of fins. Thus was obtained the key to the allocation of previously unknown proteins that bind to collagen
Search on genetic databases has shown that similar genes are in other bony fishes (including a whale shark, known as living fossils because their structure has changed little over 400 million years from the Devonian period) and in mammals, birds and amphibians – None.