The C. elegans genome is now nearing completion. I have just done a
comprehensive
search of C. elegans for P450s and named all the new sequences. There are 80
genes for
P450s in C. elegans. Some of them are in large clusters with 10-13 genes, some
of which
are probably in operons. A small number (6-7) are pseudogenes. Since the whole
genome
of C. elegans is predicted to have about 16,000 genes, these P450s represent an
unusually
large subset comprising about 0.5% of the total. Some P450 clusters are in
clusters of
olfactory receptor related genes. Perhaps the P450s are in some way acting in
concert with
the olfactory receptors. Here is an excerpt from the bibliographic page with
these
sequences.
There are 80 C. elegans P450s listed here, surpassing the known mouse and human
complements. The C. elegans genome is now officially 77% complete. However,
the
amount of sequence in the Blast searchable database at Washington Univ. is
117Mb, more
than the 100Mb size of the genome. Therefore, we can guess that this set
includes all the
P450 genes in C. elegans, but the distrubution is not even. Most P450 genes (43
genes) are
on chromosome V. see additional info on C. elegans P450s see this list. To see the actual
sequences go to the C. elegans sequence file. So
far we are missing CYP11A
and
CYP11B, CYP17, CYP19, CYP21, CYP24 and CYP27A and CYP27B. Does C. elegans
make steroids? The present evidence would suggest not. Does C. elegans have
mitochondrial P450s? There is one probable mitochondrial P450 in C. elegans on
cosmid
ZK177 named CYP44. This sequence is incomplete, missing part of the I-helix and
some
sequence upstream of that. It probably cannot code for a functional gene.
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