Snakes might not have legs, but the slithering reptiles have the DNA crucial for limb development.
Snakes have fully functional versions of limb-enhancing genes, and new research explains what the reptiles are using these genes for in lieu of legs. The DNA is used to build the phallus during embryonic development, reports Live Science.
A new study reveals that the same genetic snippets – called enhancers — that control the growth of limbs during embryonic development in mammals are part of the process of the phallus development in both mammals and reptiles. Snakes, who have no use for legs, still use the same DNA to develop their embryonic phallus, if not other extremities. As Discovery News reports, the embryonic phallus structure develops into a clitoris on females and a penis on males.
While these gene snippets were thought of as only limb enhancers in the scientific community until now, “these genetic components are actually also participating in development and driving gene expression in other body tissues,” said Doug Menke, lead study author and genetics researcher at the University of Georgia.
It tells us that we are a little bit myopic in thinking about what these limb enhancers are doing in mammals. We’ve really been thinking of these as limb enhancers, but more broadly, these genetic components are actually also participating in development and driving gene expression in other body tissues.
While the genes have lost the ability to promote the growth of limbs in snakes, they are still active in the reptiles. Scientists can now explain why snakes haven’t lost these genes during evolution – they’ve simply re-purposed them for another use.
Even as male serpents continue to build their penises from limb growth genes, it would seem several species of lady snakes have found a way to reproduce asexually.
In late September, we reported on a female snake at Missouri’s Cape Girardeau Conservation Nature Center that has twice given birth without a male snake’s assistance.