New Genes Point to Continued Human Evolution

Researchers in Greece have identified 155 new genes in humans that spontaneously arose from tiny sections of DNA, some of which date back to the ancient origin of mammals and others that are associated with human-specific diseases.

The team at Biomedical Sciences Research Center Alexander Fleming began with a previously published dataset of functionally relevant new genes and created an ancestral tree comparing humans to other vertebrate species. They tracked the relationship of these genes across evolution and found 155 that popped up from regions of unique DNA. New genes can arise from duplication events that already exist in the genome, but these genes arose from scratch.

“This project started back in 2017 because I was interested in novel gene evolution and figuring out how these genes originate,” says first author Nikolaos Vakirlis (@vakirlis), a scientist at the Center. “It was put on ice for a few years, until another study got published that had some very interesting data, allowing us to get started on this work.”

Of these 155 new genes, 44 of them are associated with growth defects in cell cultures, demonstrating the importance of these genes in maintaining a healthy, living system. Since these genes are human specific, it makes direct testing difficult. Researchers must seek another way to explore what effects these new genes may have on the body. Vakirlis and his team examined patterns found within the DNA that can hint at if these genes play a role in specific diseases.

Three of these 155 new genes have disease-associated DNA markers that point to connections with ailments such as muscular dystrophy, retinitis pigmentosa, and Alazami syndrome. Apart from disease, the researchers also found a new gene that is associated with human heart tissue. This gene emerged in human and chimp right after the split from gorilla and shows just how fast a gene can evolve to become essential for the body.

“These genes are convenient to ignore because they're so difficult to study, but I think it'll be increasingly recognized that they need to be looked at and considered,” says senior author Aoife McLysaght, a scientist at Trinity College Dublin. “If we're right in what we think we have here, there's a lot more functionally relevant stuff hidden in the human genome.”

Future studies are necessary to understand what these microgenes do and whether they might be directly involved in any kind of disease, adds Vakirlis.

The findings were published recently in Cell Reports.