New evidence from research reveals how snake genomes from species such as the king cobra, boa constrictor and the Burmese python can be embedded together to develop blueprints for limbs. Snakes exhibit the uncanny ability to move without arms or legs which is why scientists were surprised to discover this genome.
According to lead author of the study Douglas Menke from the University of Georgia's Franklin College of Arts and Sciences, snakes were not always legless through evolution. Some 100 million years ago, the reptiles only evolved to become limbless today after several generations of snake species. Since snakes became limbless through time, scientists believe that the DNA associated with snakes' limb formation would disappear or morph into another physiological feature but this new study shows that this genome is used for something else.
The team discovered that the genetic materials that are responsible for limb formation are also the same genes needed for developing external genitalia which is the reason why snakes did not let go of this genome yet.
During the experiments, researchers detected this genome from particular locations of enhancers or the noncoding DNA that dictates gene expression where they control genes that are activated in the embryonic stages. Scientists then monitored the enhancers in the limbs of mice and lizard genitalia in embryos during this experiment.
Apart from this, scientists also conducted another experiment with mice that lack one of these enhancers where it was revealed to have physical deficits when it comes to their legs and genitalia but in snakes, the enhancer only focuses on its genital development.
Menke adds that the majority of this genetic system controls the limb development which is also pivotal to the the formation of external genitalia. Snakes apparently possess these genetic blueprints for their genital development even if they do not have any limbs.
This new study can also be applied to human studies in the future, to possibly cure some human genetic disorders that involve limb and genitalia development like hand foot genital syndrome. This new study is published in the journal Developmental Cell.