Isolation of infectious particles having reverse transcriptase activity and producing hematopoietic neoplasia in Mya arenaria

The causative agent of hematopoietic neoplasia (HN) of soft shelled clams, Mya arenaria, has not been defined, though most investigators agree that the disease is caused by a small transmissible agent. Since retrovirus can demonstrate reverse transcriptase (RT) activity, we have tested purified virus for the presence of RT. RT has been found. It was active at 6 degree C and was inactive above 25 degree C. Neoplasia was accompanied by metabolic alterations: increases in uric acid, aspartate transaminase and triglycerides; decreases in hemolymph urea. The neoplastic hemocyte cell membranes showed differences in lectin binding proteins, indicating a change in cell surface glycoproteins.