LITTLE by little, we are discovering more about how our complex bodies function with so few genes – around 25,000 at the last count, rather than the 100,000 once predicted. In the latest twist, a single gene has unexpectedly been found to make two rival hormones affecting appetite: one that triggers hunger, and another that suppresses it.
The discovery suggests that single genes might exert more control than expected over entire hormonal and metabolic systems. In humans, the gene in question was once thought to make only the hormone ghrelin, a known appetite stimulant. But a study in rats…
