What do you get when you combine chicken embryos, a gene named after a video game character and some scientists? A whole new study which confirmed a key element of the evolution of the feathers, after having temporarily made that the development chicks have primitive feathers resembling those which would have been found in certain dinosaurs.
The study saw the geneticists Professor Michel Milinkovitch and the postdoctoral researcher Rory Cooper targeting the sound hedgehog (Shh) Pathway, a series of molecular signals that play an essential role in embryonic development, including feathers in chickens. The way takes its name from its main actor, Sonic Hedgehog Protein (Shh), which itself bears the name of the infamous blue creature.
Milinkovitch and Cooper had previously studied What happened when this path was stimulated in chickens, the result being embryos that developed feathers, rather than the usual scaly feet. But what happens when the Shh Is the track blocked instead? This is what the research duo sought to discover in this new study.
This involved injecting chicken embryos with a molecule that inhibits Shh Pathway – and on the new day of embryonic development, something unusual was starting to happen. Instead of the formation of the usual barbed-up feather buds, the embryos showed signs of developing something like proto-pumes.
Control images show normal development of feathers; on the right, the chicks treated with gradually higher quantities of the Shh The track blocker shows feather buds that rather resemble proto-pumes.
These are simple tube -shaped structures that would have been present in some dinosaur The species of the first Triassic, progressively evolving into the most complex feathers we see in birds today. The appearance of similar structures after changing the Shh Pathway suggests that he played a key role in this evolutionary process.
However, their appearance was only temporary.
From two weeks, the development of feathers in the embryos returned to normal. The chicks with the modified track had a few bare skin spots when they hatched, but “remarkably, these follicles (were) reactivated thereafter by seven weeks after atchargeing”, wrote the researchers, and they end up ending up with normal feathers.
“Our experiences show that if a transient disturbance in the development of foot lamps can constantly transform them into feathers, it is much more difficult to definitively disturb the development of feathers,” Milinkovitch said in a press release.
In other words, no hybrid of dino chick -pouch feathers so early – but what it illustrates is the importance of the Shh go towards feather Development, and how it also seems to have evolved extreme resilience.
Obviously, during the evolution, the network of interaction genes has become extremely robust, guaranteeing the appropriate development of feathers even under substantial genetic or environmental disturbances, ” added Millinkovitch. “The big challenge is now to understand how genetic interactions are evolving to allow the emergence of morphological new products such as proto-fores. ”
The study is published in Biology PLOS.