JUST HATCHED Scientists have zoomed in on the internal structure of the chicken eggshell to figure out how it can protect developing chicks while eventually letting them break free. (sciencenews.org)
To find out if that happens in the face, a team led by developmental biologist Jill Helms of the University of California, San Francisco, applied a molecule that blocks the retinoic acid receptor to the head region of developing chicks. (sciencemag.org)
They transplanted embryonic tissue from the legs to the wings of 3 1/2 - day - old developing chicks and vice versa and watched how the transplanted tissue developed. (sciencemag.org)