Application of differential display polymerase chain reaction to the study of neoplasms of feral marine bivalves

Pathological conditions, especially neoplasms, in feral animals have been shown to be indicators of environmental degradation by pollutants. A gonadal neoplasm in soft shell clam (Mya arenaria) has been identified among certain populations of clams in Maine, but the etiology of these neoplasms is unknown. We have undertaken a study of these neoplasms to determine whether they may be a result of exposure to contaminants. One approach we have taken is to identify genes that are differentially expressed by neoplastic cells. Such genes may be part of the molecular pathway that is responsible for the neoplastic phenotype, and their identification could shed light on the etiology of the neoplasm. By using differential display polymerase chain reaction (ddPCR), we found at least four genes that are involved in biosynthetic activities related to cell growth and proliferation. These findings demonstrate that ddPCR can be a useful tool to study neoplasms in feral animals, especially for species that have not been genetically well characterized.