In the Science paper, researchers from more than 40 institutions report that the Physcomitrella genome contains just under 500 million nucleotides and possesses nearly 36,000 genes, which is about 50 percent more than are thought to be in the human genome. Physcomitrella is the first nonvascular land plant to be sequenced. Vascular plants lack specialized tissues (phloem or xylem) for circulating fluids, instead possessing specialized tissues for internal transport. They neither flower nor produce seeds, but reproduce via spores.
Mishler said that Physcomitrella is well-placed phylogenetically to fill in the large gap between the unicellular green alga Chlamydomonas, also sequenced by the Joint Genome Institute, and the flowering plants.
"Having the full Physcomitrella genome available to the public greatly advances bioinformatic comparisons and functional genomics in plants," said Mishler, who is part of a major effort within the Berkeley Natural History Museums - a consortium of six museums at UC Berkeley - to link the two. "This is a great example of how phylogenetics can integrate with functional and applied studies."
Mishler noted that the draft genome sequence is only the beginning. Plant scientists plan to meet regularly to assign specific functions to the newly identified genes based on experiments in the moss or by analogy with related genes in other organisms. This experimentation process is called annotation. The first so-called annotation jamboree was hosted in June 2006 by UC Berkeley and the Joint Genome Institute, and another is planned in Finland next year.
|Contact: Robert Sanders|
University of California - Berkeley