Some time ago it was believed that new genes originated, at least partially, from other genes; for instance, from the duplication of existing genes. But recently it has been seen that there are certain genes, those called de novo genes, that originate in genomic regions that didn’t contain any genes previously.
A study published in arXiv.org, led by Mar Albà, the coordinator of the Group on Evolutionary Genomics from the Research Programme on Biomedical Informatics (GRIB) from IMIM and the UPF and an ICREA Professor, and with the collaboration of scientists from different centres at the PRBB (Barcelona Biomedical Research Park), has revealed there are hundreds of de novo genes originated in humans, many of which where unknown until now. Some of these genes are coded through small proteins that are expressed in the brain or in germinal cells.
How do these genes originate from nothing?
Researchers have compared the transcriptome and the genome of several mammal species, including humans, chimpanzees, macaque monkeys and mice, and have discovered that de novo originated genes have acquired DNA motifs, a set of structures that are involved in gene expression, to which transcription factors are bound. Albà explains that “The formation of these new genetic transcription promoters, due to the accumulation of random mutations, would thus be determining for the emergence of new genes, unique in the human species”.
In this study by the group led by Mar Albà, 600 genes have been identified that would presumably have originated de novo in the human genome. Some of these genes would have acquired new functions and might be involved in pathologic processes, which will be the object of future studies, “The study proves that the evolution of new genes is an ongoing process that allows organisms to acquire new functions and to change during evolution”, the researcher concludes.
You can read more on this subject on the blog of the Group on Evolutionary Genomics at this and this post and also the article signed by Emily Singer “A Surprise Source of Life’s Code”, which offers an interesting perspective on the history of de novo genes.