A team of 150 researchers from the US and Sweden have published a series of studies in the journal Science, revealing that at least 10% of the human genome is highly conserved across species, with many of these regions occurring outside of protein-coding genes. The researchers discovered that over 4,500 elements are almost perfectly conserved across more than 98% of the species studied.
Most of the conserved regions, which have changed more slowly than random fluctuations in the genome, are involved in embryonic development and regulation of RNA expression. Meanwhile, regions that have changed more frequently are linked to an animal’s interaction with its environment, such as through immune responses or the development of its skin.
The researchers identified regions of the genome that are most conserved, or unchanged, across mammalian species and millions of years of evolution. These regions are likely biologically important and could play a role in understanding how certain species achieve extraordinary feats. The team also pinpointed genetic variants that are more likely to play causal roles in rare and common human diseases.
In addition to identifying key genetic regions important for biodiversity and health, the team found parts of the genetic basis for uncommon mammalian traits such as the ability to hibernate or sniff out faint scents from miles away. The researchers also discovered that mammals with fewer genetic changes at conserved sites in the genome are at greater risk for extinction.
Through this research, the team demonstrated how comparative genomics can help scientists better understand the parts of our genome that are functional and how they might influence health and disease. They concluded that having just one reference genome per species could help identify at-risk species. However, less than 5% of all mammalian species currently have reference genomes, so further work is needed to develop these methods.
The team collected DNA samples from over 50 different institutions worldwide, including many from threatened or endangered species provided by the San Diego Wildlife Alliance. These findings could provide a deeper understanding of how genetics influences health and disease and may have important implications for conservation efforts.