A quirk of evolution means a particular gene stays 'switched on' for longer than usual during snakes' embryonic development
Snakes owe their long, slithery bodies to a single gene, research has shown. The Oct4 gene regulates stem cells and affects the growth of the middle part, or trunk, of a vertebrate's body.
In snakes, a quirk of reptilian evolution has resulted in Oct4 remaining "switched on" for longer than usual during embryonic development.
Dr Rita Aires, from the Instituto Gulbenkian de Ciencia (IGC) in Lisbon, Portugal, said: "The formation of different body regions works as a strong-arm contest of genes. Genes involved in trunk formation need to start ceasing activity so that genes involved in tail formation can start working.
"In the case of snakes, we observed that the Oct4 gene is kept active during a longer period of embryonic development, which explains why snakes have such a long trunk and a very short tail."