After more than two decades of continuous effort, an international research team has achieved a major breakthrough in genomics, successfully decoding the complete genetic code of six species of great apes (primates).
The results of the study, published in Nature, will help inform conservation efforts for these species and, more importantly, expand our understanding of the differences between humans and apes.
The genome is the complete set of DNA instructions contained within a cell. Sequencing it means identifying the identity and order of the building blocks in each DNA molecule. After scientists successfully sequenced the human genome in 2001, they turned directly to the genomes of great apes, our closest ancestors.
According to Professor Katerina Makova of the University of Pennsylvania, who has worked for 25 years to assemble complete genome sequences of apes, understanding the genomes of non-human apes is useful not only for studying evolution. There are also benefits for medicine, for example, as scientists study changes in apes' DNA that make them more resistant to certain diseases such as AIDS.
She explained that portions of monkey genomes had previously been decoded, but no one had been able to assemble the complete sequence of any species. In the new study, Makova and her colleagues used advanced methods and algorithms that allowed them to assemble long segments into a continuous sequence, starting from one end of each chromosome and ending at the other.
Using these methods, researchers decoded the genomes of six species: chimpanzees, bonobos, gorillas, Bornean orangutans, Sumatran orangutans, and siamangs (a type of gibbon).
Between 770 and 1,482 potential new genes were identified in each of the species, and unusual DNA structures were discovered in previously unstudied areas.
These results are particularly important for analyzing the genetic diversity of endangered species: all six species studied are threatened. In the future, these data could help identify genes critical to the species' survival.
The data collected by Makova and her team is now available to scientists around the world. Molecular biologist Henrik Kassmann of the University of Heidelberg said, "We now have the best available genomes of great apes, providing an important reference for future studies.