Do Rats Share DNA With Humans?
WouterThe researchers analyzed the gene sets from rats and mice, and discovered that they share a significant amount of DNA. According to the scientists, rat and mouse genomes contain one-fourth of the same DNA. Despite having the same number of genes, the two species have significantly different behavior, as well as varying levels of mutation. The findings of the study provide clues to the origins of the differences between the two species.
The researchers used the genome of the laboratory rat to compare its sequences with those of mice and humans. The results were astounding: the rat’s genome matches that of humans and mice 90 percent of the time. This enables researchers to more easily discover and analyze the genes that cause different human diseases.
Researchers have also discovered that the three mammalian genomes share a high percentage of genes. In fact, ninety percent of rat genes are orthologs of their human and mouse orthologs. The remaining genes are associated with gene-family expansions, which are the major source of genetic variation between humans and rats. These expansions likely reflect differences in reproduction and chemosensation. In addition, the rat genome contains a higher number of proteins than those in mouse’s genome. This difference could potentially have functional implications in olfactory discrimination.
These recent discoveries have given scientists a clearer picture of the evolution of mammalian genomes. The rat genome sequence is now the third complete mammalian genome and was published in a major scientific journal. The comparison of the rat genome with those of humans and mice is expected to shed light on the details of mammalian evolution.
