By tweaking a particular gene, scientists have found a way to permanently transform the scales on a chicken’s feet into feathers. The benefits offer new insight into the bird’s evolutionary origins from dinosaurs.
“Like birds, it is clear currently that several dinosaurs had been partially covered with feathers as properly as scales,” mentioned Michel Milinkovitch, a professor in the Division of Genetics and Evolution at the University of Geneva and co-author of the new investigation. “In birds, it is comparable. So, by altering this gene, we can really expand or reduce the proportion of the physique that is covered by feathers or scales based on when this gene is specifically expressed.”
To carry out this genetic switcheroo, scientists in Switzerland targeted the sonic hedgehog gene (Shh), which controls a signaling pathway that determines the improvement of particular traits although at the embryonic level. This consists of the brain and spinal cord limbs and skin appendages, like scales and feathers, according to the study, published May possibly 17 in the journal Science Advances. (And, yes, Shh is named just after the titular character of the well-known video game.)
In the lab, scientists employed a approach identified as “egg candling,” which includes working with a light supply to illuminate the blood vessels inside an egg. This enabled them to recognize a appropriate vessel to straight inject the building embryo with a molecule that activates the Shh pathway. For the study, they employed broiler chickens (Gallus gallus domesticus), which are raised for industrial meat production, according to a statement.
Connected: Domesticated chickens could wipe out their wild ancestors — by possessing sex with them
“We carried out the injection on day 11, which is the precise time when scales generally arise on the embryo,” lead author Rory Cooper, a postdoctoral fellow in artificial and all-natural evolution at the University of Geneva, told Reside Science. “If we carry out the injection even 1 day also late, the embryo has currently begun building scales.”
Right after the eggs hatched, the scientists noticed the formation of downy juvenile feathers on the chicks’ feet. These supersoft feathers had been comparable to the feathers covering the rest of their bodies, according to the statement.
“The impact is seriously clear after they hatch,” Cooper mentioned. “And the alter lasts. After the chickens create the feathers, they never go back to possessing scales on the targeted location.”
The researchers had been shocked at how effortless it was to shape-shift the chickens’ feet and mentioned it gives the group a new understanding of how these animals evolved.
“Feathers are a function of alter,” Milinkovitch told Reside Science. “In dinosaurs, feathers could have been employed to regulate the animal’s internal temperature or as a colorful show. Flight came later. By altering the expression of 1 gene, we had been in a position to generate a cascade of developmental effects that triggered feather development, providing new insights into the evolution of these animals.”