Berkeley -- The newly sequenced genome of a one-celled, planktonic marine organism, reported today (Thursday, Feb. 14) in the journal Nature, is already telling scientists about the evolutionary changes that accompanied the jump from one-celled life forms to multicellular animals like ourselves.
In the Nature paper and a complementary Science paper also released this week, University of California, Berkeley, biologists Nicole King, Daniel Rokhsar and their colleagues present their first draft of the genome of a choanoflagellate (ko AN oh FLA je let) called Monosiga brevicollis, and their first comparisons with the genes of multicellular animals, the so-called metazoans.
The sequencing and analysis was performed by the Department of Energy Joint Genome Institute (JGI) in Walnut Creek, Calif., in collaboration with researchers from UC Berkeley and eight other institutions.
According to King, biologists know almost nothing about these organisms, aside from the fact that they are an important food for krill, which are the main source of food for baleen whales, and that, by consuming large quantities of bacteria, choanoflagellates play a major role in the carbon cycle of the oceans. Yet, because choanoflagellates and animals shared a common ancestor between 600 million and a billion years ago, they hold a key to understanding the origins and evolution of animals.
"Choanoflagellates are the closest living unicellular relatives of animals and, as such, can help us learn about our history and the history of life on Earth, which has been dominated by one-celled organisms," said King, an assistant professor of integrative biology and of molecular and cell biology, and a 2005 MacArthur "genius" Award winner. "They help shed light on the biology and genome content of the unicellular organisms from which we evolved."
One finding confirmed by the sequencing is that choanoflagellates have many genes that, in animals, produce pr
|Contact: Robert Sanders|
University of California - Berkeley