Scientists Sequence the Marmoset Genome: DNA Sheds Light on Primates

Scientists are learning a bit more about the marmoset, the social, furry primate that's known for its rapid reproductive system. They've sequenced the animal's genome, shedding light on primate biology and evolution.

"We study primate genomes to get a better understanding of the biology of the species that are most closely related to humans," said Jeffrey Rogers, one of the researchers, in a news 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."

By sequencing the genome of the marmoset, the researchers learned a bit more about the animal's unique genetic characteristics. Most interesting was the finding of several genes that are likely responsible for the marmoset's ability to consistently reproduce multiple births.

"Unlike humans, marmosets consistently give birth to twins without the association of any medical issues," said Kim Worley, one of the researchers. "So why is it okay in marmosets but not in humans where it is considered high risk and associated with more complications?"

The researchers found a gene, called WFIKKN1 that exhibited changes associated with twinning in marmosets. In fact, the gene may act like some kind of critical switch between multiples and single pregnancies. In addition, the scientists examined changes associated with dizygotic (or fraternal) twins in marmosets and how they exchange blood stem cells, called hermatopoietic stem cells, in utero, which leads to chimerism.

"This is very unusual," said Rogers. "The twins are full siblings, but if you draw a blood sample from one animal, between 10 and 50 percent of the cells will carry the sibling's DNA. Normally, fraternal twins do not share the same DNA in this way, and in other animals this chimerism can cause medical problems but not in marmosets. It is very unique."

The findings reveal a bit more about marmosets, and also about primate evolution in general. In addition, the sequence lays the foundation for further biomedical research using marmosets.

The findings are published in the journal Nature Genetics.