Researchers from the Oregon Health & Science University have finally mapped the genetic sequence of the gibbon. The new DNA analysis provided insight on its complex evolution, which has been the subject of debate among scientists for decades.
Lead author of the study Lucia Carbone, who is assistant professor of behavioral neuroscience in the OHSU School of Medicine and assistant scientist in the Division of Neuroscience at OHSU's Oregon National Primate Research Center, worked with her colleagues for more than two years studying the chromosomal rearrangement of the gibbons. The gibbon ape is one of the closest relative of humans but is considered more complex than humans and other apes because of its complex chromosomal evolution.
"You might think about chromosomes as constructions made of different plastic toy bricks. In the rearrangement, one or more toy pieces separate from the others and reattach in a different orientation or location. Or, they might get lost or duplicated," said Carbone. "We know that these types of events have been occurring in the other apes, including humans, but gibbons show a much higher frequency. One of our goals while analyzing the genome was to try to identify the cause of this instability."
Scientists are eager to sequence the genome of the gibbon, not just to learn more about this species, but to gather more information as how humans evolve and trace the origins of diseases. The chromosomal rearrangements observed in the gibbons can lead to birth defects and human cancers. However, the researchers were surprised that such defects were not seen in gibbons, and they would like to know how the species were able to overcome these defects.
Carbone's team identified a LAVA element, a repetitive DNA sequence that is unique in gibbons, which could explain how the ape survived its complex evolution.
"The LAVA element is an evolutionary novelty that is only present in the DNA of gibbon species," Carbone said. "We think that it played a major role by increasing the 'errors' during cell division and chance for chromosomal rearrangements."
Further details of the study were published in the Sept. 11 issue of Nature.
