Conservation of cancer genes in the marine invertebrate Mytilus edulis

Mussels are susceptible to a wide range of environmental
toxicants, including carcinogens, and thus are often
employed as bioindicator species. To elucidate the molecular
aetiology of such neoplastic damage, we have cloned
Mytilus edulis homologues of the vertebrate ras protooncogene,
and p53 tumor suppressor gene. The M. edulis
ras cDNA encodes a predicted protein of 184 amino
acids. The DNA sequence analysis with vertebrate ras
sequences demonstrates that the M. edulis ras cDNA is
highly conserved in regions of functional importance, including
mutational hot spots. The partial p53 sequence also
demonstrates that M. edulis p53 is highly conserved in
two regions of functional importance and that these regions
also include four of the five mutational hot spots for this
gene. In contrast, the M. edulis p53 sequence shows little
similarity to the other published invertebrate p53-like
sequences. The cancer gene sequences characterized
herein will allow development of specific biomarkers of
genotoxic damage.