D. Nelson Feb. 22, 2008
The Monosiga genus contains members of the Choanoflagellates. These are single celled organisms thought to descend from the common ancestor to all animals. These cells resemble the collar cells of sponges.
There is a Monosiga brevicollis genome project at JGI. Go there now!
The genome project paper was just published:
The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans.
Nature. 2008 Feb 14;451(7180):783-8.
Click here for the Pubmed link PMID: 18273011
In addition there is a Monosiga ovata EST project.
A phylogenomic investigation into the origin of Metazoa
Iñaki Ruiz-Trillo, Andrew J. Roger, Gertraud Burger, Michael W. Gray and B. Franz Lang. MBE Advance Access published online on January 9, 2008
Molecular Biology and Evolution, doi:10.1093/molbev/msn006
The Monosiga ovata genome is being sequenced at Washington University.
The P450s assembled from these species are linked below.
Monosiga brevicollis P450s (a marine choanoflagellate)
Monosiga ovata P450s (a freshwater choanoflagellate)
Monosiga brevicollis has 9 P450s including CYP51A1 and Monosiga ovata has 8 P450s including CYP51A1. Most of the other P450s are different between the two species.
M. brevicollis has a CYP745 (similar to Chalmydomonas and Volvox) and it has
CYP704 similar to plants and microalgae like Ostreococcus CYP704B1.
It is not clear if these genes are derived from the diet of Monosiga or if they are in the Monosiga genome. Monosiga does eat algae.
These genes are not found in the ESTs of M. ovata.
CYP745 is found in Proterospongia sp. A colonial choanoflagellate.
M. ovata has a CYP710D1 gene similar to CYP710 sequences from plants.
This sequence is not found in M. brevicollis.
The origin of these plant related sequences in the ancestor of animals is not clear.
Perhaps the ancestor of animals had some plant P450 genes present, or
perhaps we are what we eat.