BATON ROUGE Since the launch of the Human Genome Project, which released a first draft of the entire sequence of human DNA in 2001, many researchers have dedicated themselves to creating a library of comprehensive, species-specific genetic sequence "maps" available for study. Scientists at LSU recently took part in a multi-institutional effort spearheaded by the Broad Institute of MIT and Harvard University to sequence the complete genome of the gray, short-tailed opossum, Monodelphis domestica.
As the first marsupial, a mammal equipped with a special "pouch," to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. The results will be published in the journal Nature on Thursday, May 10.
Marsupials diverged from a common ancestor with placental mammals, a group including humans, approximately 180 million years ago. Marsupials and placental mammals are more closely related to one another than to any other vertebrate model species, such as birds, amphibians or fish, yet marsupials are also genetically distinct from all current mammalian biomedical research models. This makes the marsupial an integral part of evolutionary and biomedical studies.
Kangaroos of Australia and the North American opossum, which is abundant in Louisiana, typically come to mind when one thinks of marsupials. However, Monodelphis domestica, a South American opossum, was chosen for genome sequencing because it is the predominant laboratory-bred research marsupial in the world and therefore represents an important model organism for comparative genomics. Studies in this species will help to identify genome features common to all mammals and will also help to pinpoint specific differences between placental and non-placental mammals.
"Mapping the opossum genome is a significant achievement for many reasons," said Mark Batzer, Andrew C. Pereboom Alumni Departmental Professor of Biological Sciences at LSU, and on
Contact: Mark Batzer
Louisiana State University