RESEARCHERS have identified genetic material that may have played a key role
when vertebrates emerged from the sea onto the land. A gene vital for the proper
development of fingers and toes in vertebrates has two “promoters”—regions
of DNA that affect its expression. Susan Dymecki and Scott Baur of the Harvard
Medical School found that one affects expression in the brain and one in the
skeleton.
If the skeleton promoter is blocked in a mouse, its digits do not develop
although the brain does (Development, vol 126, p 605). “What’s
tantalising is that this promoter may have been…
