How legs were lost during snake evolution скачать в хорошем качестве

How legs were lost during snake evolution

Most snakes are completely limbless, but some snakes diverged from the lineage leading to the advanced snakes before legs were completely eliminated. Pythons are a group of snakes that retain a pelvis and a small remnant of the femur, known as the spur. Francisca Leal and Marty Cohn at the University of Florida discovered that deletions in an enhancer of the Sonic hedgehog gene are responsible for the arrest of limb development in python embryos. Unexpectedly, python embryos form pre-cartilaginous models of the entire leg skeleton, down to the foot, but these embryonic leg structures degenerate before hatching, leaving only the spurs. Check out the paper at http://www.cell.com/current-biology/f... F. Leal and M.J. Cohn (2016). Loss and Re-emergence of Legs in Snakes by Modular Evolution of Sonic hedgehog and HOXD Enhancers. Curr. Biol. 26. And read more great research at http://www.cell.com/current-biology/home.