Jaws in Progress

The human bite is almost as strong as that of a pitbull. Researchers investigating how our powerful jaws develop looked to mouse embryos for genetic clues. Focusing on the lower jaw, they looked at which genes were active in the cells from which it forms, namely a specific group of neural crest cells. They discovered two major signalling proteins were involved in directing lower jaw development, Shh and BMP4. In genetically altered mice in which Shh signalling was blocked in these neural crest cells, BMP4 signals spread further, indicated by the pink staining in the developing mouse jaw (pictured) when compared to what happens normally. These mutant mice subsequently had defects in jaw development, with less tongue tissue and expanded jawbone tissue. Shh therefore appears to rein in BMP4 signalling so that the jaw develops correctly.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Image from work by Jingyue Xu and colleagues
• Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
• Image originally published under a Creative Commons Licence (BY 4.0)
• Published in eLife, January 2019