New World Monkey DNA Sheds Light on Primate Evolution

A team of scientists has completed the genome sequence of the common marmoset - the first sequence of a New World monkey - shedding light on primate biology as well as evolution.

"We study primate genomes to get a better understanding of the biology of the species that are most closely related to humans," study lead author Dr. Jeffrey Rogers, associate professor in the Human Genome Sequencing Center at Baylor, said in a press release.

"The previous sequences of the great apes and macaques, which are very closely related to humans on the primate evolutionary tree, have provided remarkable new information about the evolutionary origins of the human genome and the processes involved."

In past studies, researchers had only sequenced the DNA of primates more closely related to humans. But by understanding the marmoset genome, a more distant relative of humans, scientists can not only broaden their ability to study the human genome but also better understand the evolutionary relationship between the two species.

"Each new non-human primate genome adds to a deeper understanding of human biology," added Dr. Richard Gibbs, who was involved in the study.

Marmosets appear to frequently give birth to twins, although without the usual risks and complications associated with humans when they produce twins.

Scientists found that the marmoset gene WFIKKN1 exhibits changes associated with "twinning" in these monkeys.

"From our analysis it appears that the gene may act as some kind of critical switch between multiples and singleton pregnancies, though it is not the only gene involved," Rogers explained, who added the finding could apply to studies of multiple pregnancies in humans.

Marmosets also exhibit a unique social system involving alloparenting, in which the dominant male and female are the primary breeders for the family, while their relatives care for their offspring.

Interestingly, the relatives who provide the care are reproductively suppressed, said Worley.

"This species is clearly adapted to rapid reproduction and to the potential for rapid population expansion," Rogers added.

The study also provides new information about their small body size and microRNAs, small non-coding RNA molecules that function to regulate gene expression.

The sequence lays the foundation for further biomedical research using marmosets, according to Rogers.

"Researchers may have been more reluctant to study the marmoset due to lack of basic information," he said, "but this genome sequence opens new avenues for future research relevant to various aspects of human health and disease."

The findings were published in the journal Nature Genetics.