THE ESSENTIAL
- Evolution, spawned in part by natural selection, has gradually transformed us into our current state and continues to bring changes to our DNA.
- Certain traits created by genetic mutations help an organism survive or reproduce.
- When these mutations are more likely to be passed on, they increase in frequency.
An international team of scientists has identified 155 “microgenes” that have arisen spontaneously within the human lineage from tiny sections of DNA since our species Homo sapiens split with our ancestors. Some date back to ancient mammalian origins and a few are linked to human-specific illnesses that we have suffered in the past. their study, published in the journal Cell Reportsopens the door to a more detailed exploration of the effects of genes on the body.
An ancestral tree to better understand the evolution of our genes
Taking the dataset from previous studies, the researchers created an ancestral tree comparing Homo sapiens to other vertebrate species. He showed that some genes appeared from scratch and did not arise from duplication events that already existed in the genome of early Homo sapiens.
“This project started in 2017 because I was interested in the evolution of new genes and understanding the origin of these genes”says first author Nikolaos Vakirlis, a scientist at the Alexander Fleming Biomedical Science Research Center, in a communiqué.
Some genes are caused by diseases unique to humans
The results of their analyzes show that among these 155 new genes, 44 are associated with growth defects in cell cultures, demonstrating the importance of these genes in maintaining a healthy and living organism. Three others were linked to diseases unique to humans. Two had DNA markers indicating links to muscular dystrophy and retinitis pigmentosa, which cause vision loss. Another contained a chemical form associated with an increased risk of dwarfism (Alazami syndrome).
In addition to diseases, researchers have also discovered a new gene associated with human heart tissue. This gene appeared in humans and chimpanzees just after the split with the gorilla and shows how quickly a gene can evolve to become essential for the body. “It will be very interesting in future studies to understand what these microgenes might be doing and whether they might be directly involved in any type of disease.”emphasizes Dr. Vakirlis.