Source of Evolutionary Differences Among Species Uncovered
University of Toronto Faculty of Medicine researchers have uncovered a genetic basis for fundamental differences between humans and other vertebrates that could also help explain why humans are susceptible to diseases not found in other species. Scientists have wondered why vertebrate species, which look and behave very differently from one another, nevertheless share very similar repertoires of genes. For example, despite obvious physical differences, humans and chimpanzees share a nearly identical set of genes.
The team sequenced and compared the composition of hundreds of thousands of genetic messages in equivalent organs, such as brain, heart and liver, from 10 different vertebrate species, ranging from human to frog. They found that alternative splicing — a process by which a single gene can give rise to multiple proteins — has dramatically changed the structure and complexity of genetic messages during vertebrate evolution. The results suggest that differences in the ways genetic messages are spliced have played a major role in the evolution of fundamental characteristics of species.