Gene regulation makes the human

A stretch of non-coding DNA revs up genes during development

Genes alone don’t make the man — after all, humans and chimps share roughly 98 percent of their DNA. But where, when and how much genes are turned on may be essential in setting people apart from other primates.

A human version of a stretch of DNA, when inserted into a mouse embryo, cranks up the activity of genes in the developing thumb (shown blue). But this activity was much lower with the chimp or rhesus macaque version of the same DNA sequence. The difference could point to the kinds of developmental changes that make us human.
THUMBS UP A human version of a stretch of DNA, when inserted into a mouse embryo, cranks up the activity of genes in the developing thumb (shown blue).