the modern humans We are evolutionarily different from our ancestors chimpanzee Nearly 7 million years ago, but we’re still evolving, science has found in a new study.
Experts from the Alexander Fleming Biomedical Sciences Research Center (BSRC Flemming) in Greece and Trinity College Dublin, Ireland, have identified 155 new genes Within the human race that arose spontaneously from small fragments of our DNA.
Many of them seem to play crucial roles in our biology, revealing how completely new genes can rapidly evolve into essential ones. Some of these new genes trace back to ancient mammalian origin, and it is speculated that part of these “microgenassociated with certain human diseases.
New genes usually arise through well-known mechanisms, such as duplication events, whereby our epigenetic machinery produces copies of pre-existing genes that may end up with new functions over time. But the 155 microgens identified in this research published in Cell ReportsIt appears to have emerged from scratch, in stretches of DNA Before it does not contain instructions Used by the body to build molecules.
Since the proteins that are thought to encode these new genes will be incredibly small, so are these DNA sequences. Hard to reach and the study. Therefore, they are often overlooked in research. This project started in 2017 because I was interested in the evolution of new genes and in discovering how they arise. It was frozen for a few years, until another study was published with some very interesting data, which allowed us to begin this work,” explained evolutionary geneticist Nikolaos Vakierlis, from BSRC Flemming in Greece.
that Another studyPublished in 2020 by a team of researchers at the University of California, San Francisco, it catalogs a mound of tiny proteins produced by non-coding regions once described as “junk DNA.” The team behind this new study subsequently created a genetic ancestry tree to compare those exact sequences found in our genome with those in 99 other vertebrate species, tracing the evolution of genes over time.
Some of the new “micromolecules” identified in this new study can be traced back to the early days of mammals, while others are more recent additions. The researchers found that two of the genes identified in the study arose from a split between humans and chimpanzees.
We sought to identify and examine cases in the human lineage of small proteins that have evolved from previously non-coding sequences and acquired functions immediately or shortly thereafter. This is doubly important: for our understanding of the intriguing and still largely enigmatic phenomenon of de novo gene birth, but also for our appreciation of the full functional potential of the human genome. “
Microproteins are already known to have a wide range of functions, from helping to regulate the expressions of other genes to joining forces with larger proteins, including our cell membranes. However, while some microproteins perform vital biological tasks, others are simply useless. “When you start to get into these small sizes of DNA, they’re really at the limit of what can be interpreted from the genome sequence, and they’re in this area where it’s hard to know if it’s biologically important,” added Dublin geneticist Aoife McClesagt, of Trinity College.
A gene involved in building heart tissue arose when the common ancestor of humans and chimpanzees diverged from that of gorillas. If this microbiome gene did in fact arise in the last few million years, it is striking evidence that these evolving parts of our DNA can quickly become essential to the body.
The researchers then tested the sequencing’s functionality by deleting genes, one by one, in cells grown in the lab. Forty-four cell cultures showed developmental defects, confirming that the now-lost fragments of DNA play an important role in our continued work.
In other comparative analyses, the researchers also identified variants known to be associated with disease in three of the novel genes. The presence of these coincidental mutations at a single base locus in the DNA may indicate an association between muscular dystrophy, retinitis pigmentosa, and Alazami syndrome, but further research will be required to elucidate these relationships.
In light of modern technology and medicine, estimating the amount of biological change humans have experienced as a species at the hands of natural selection can be challenging. But our physical condition has been largely shaped by the stresses of diet and disease over thousands of years, and will undoubtedly continue to adapt even in a technologically advanced world.
It is not yet clear how the spontaneous creation of new genes within the non-coding region occurs, but with our new ability to track these genes, we may be closer to finding out.
“If we are right in what we think we have here, there are many functionally related things hidden in the human genome,” geneticist McClesagt concluded cryptically.