Despite decades of advancements in genomics, we still don’t know what most of our DNA does. But an ambitious international research collaboration is providing new answers about how genetics shapes human health and disease, with help from an unlikely source — a menagerie of mammals.
The findings, reported in a set of 11 studies published on [April 27] in the journal Science, come out of the Zoonomia Project, which compared the genomes of 240 mammalian species. The list of sequenced creatures reads a bit like the passenger manifest of Noah’s Ark: Amazon river dolphins, greater mouse-eared bats, fat-tailed dwarf lemurs, horses, humans, and more.
Researchers found stretches of DNA common to these animals that remained largely unchanged across 100 million years of evolution — a telling indicator that these sequences have an important function. The scientists estimated that a minimum of 10.7% of the human genome is functional, on the higher end of estimates of 3% to 12% from previous studies.
Most of this so-called constrained DNA does not code for the production of proteins — the building blocks and machinery of cells — and roughly half of it is in regions of the genome that researchers don’t understand at all. But the studies offer early hints that mutations in these evolutionarily conserved regions could play a key role in disease, such as certain brain cancers.
