A premature baby being cared for by a nurse

Childbirth and pregnancy might be influenced by variations in the progesterone-receptor gene, which shows wide diversity in humans. Credit: BSIP/UIG/Getty

Evolution

Gene important in pregnancy shows evolution in action

Human populations have different forms of a gene encoding a hormone receptor.

A pregnancy-related gene shows different forms in different human populations — a result of relatively recent evolution.

Mutations in the gene PGR, which encodes a protein that senses the hormone progesterone, might be linked to preterm birth and ovarian cancer. A team led by David Stevenson and Gary Shaw at Stanford University School of Medicine in California examined variations in the PGR gene in human groups from far-flung locales.

The researchers found that East Asian groups carry many fewer versions of the gene than do Europeans, which indicates that the gene has continued to evolve since the split between the ancestors of these populations. This recent genetic change might have conferred protection against preterm birth. The study also traced a potentially harmful PGR mutation to Neanderthal genomes, suggesting that humans acquired the mutation through interbreeding.