Feathers , scales , spines , and haircloth are all exercise of keratinized skin appendages developed by vertebrates . They are very dissimilar from each other , but they share former developmental mental process during the embryologic stages . Researchers at the University of Geneva have now worked out that it is amazingly promiscuous to uprise plume where there should be scales , just by bear upon one gene ’s locution .
All the keratinized skin appendages develop from a localized thickener on the peel aerofoil and the expression of particular cistron . An important one has a silly name : transonic hedgehog(Shh ) . The name came from the breakthrough that a mutation on it gives drosophila larvae multiple points , a bit like the spines of a hedgehog . When activated this footpath , allows chickens to grow feathering where they usually do not .
‘ ‘ Our results indicate that an evolutionary leap - from scales to feather - does not require large changes in genome composition or expression . Instead , a transient variety in expression of one gene , Shh , can produce a cascade of developmental events go to the formation of feathers instead of scales , ’’ like source Dr Michel Milinkovitch say in astatement .
There are some Gallus gallus varieties with plumage on their feet but it is not a common trait . And why some have it and most do n’t is not precisely fully understand . The investigator discover that a single intervention on chicken fertilized egg when they are still in the egg is enough to touch off the formation of feathers on their feet .
“ We used the Greco-Roman technique of ‘ ball candling ’ , in which a muscular torch illuminates line vessels on the inside of the eggshell . This allowed us to precisely process chicken embryos with a particle that specifically spark off the Shh pathway , injected directly into the blood stream , ’’ explained first author Dr Rory Cooper , a post - doctoral investigator in Michel Milinkovitch ’s laboratory .
The two scientists also treat embryos with a control solution that did not spark the Shh nerve tract . RNA analytic thinking showed that in the group that got the Shh - activating molecule , the pathway was aerate immediately and persistently , create feather like those on the rest of the consistence . These are regenerated when mislay and automatically replaced when the wench becomes an adult .
The work shows that the Shh pathway is central to the shift of scales into feathers . The variety of the various skin appendages in nature , as well as the organic evolution of birds from avian dinosaur , likely pass through this nerve pathway .
The work was published in the journalScience Advances .
