Marmosets are marvelous !
The New World monkeys have their first full genome sequence. While the marmoset, Callithrix jacchus, is hardly typical, its rapid reproduction (with multiple births-80% are twins) and its physiology are unique. Jeffrey Rogers works in the Baylor Genome Sequencing Center in Houston where the research was carried out, and hopes this genome will shed more light on the evolution of the human genome.
He will see his hopes fulfilled if this distant branch of the primate tree compares directly with other species such as ourselves. He believes that one gene acts as a critical switch for a multiple or a single birth. The study of multiple births in the human species needs links such as this to progress. At the moment, we have much less successful twin growth and survival than the marmoset, who find it a breeze!
One unique characteristic of marmosets is the intriguing swapping of stem cells between dizygotic twins during development.. They can carry between 10 and 50% of their siblings DNA in their cells, which should cause the individuals problems, but it doesnt. Another feature of marmosets is their society, which, like that of wolves, has a dominant pair. All relatives including the males care, carry and support the young of the pair, but are suppressed from sexual reproduction themselves.
Such adaptation responds well in situations such as disturbed forest habitats. Rapid population expansion is possible with support from, the family. Feeding habits and the diet must also fit well with these colonists. Small bodies could help too, with positive selection for 5 genes involved in low growth hormone production. This small size has a cluster of metabolic-rate change genes and body temperature adaptations associated with it too. Dr Kim Worley led the multi-talented international team from a consortium including the Universities of New Jersey, Houston, Washington and Texas (at San Antonio) published as- The common marmoset genome provides insight into primate biology and evolution, in Nature Genetics.
The common marmoset lived originally in NE Brazil but its quite an invasive species and is now common far to the south, and indeed in cities such as Rio and Buenos Aires. The other members of the marmoset family include the tamarins and of course the dwarf marmoset Cebuella pygmaea