Studies on the incidence of rat ileocecal malignant immunocytoma: vertical transmission of the high tumour incidence.

Monoclonal immunoglobulin-secreting tumours (immunocytomas, myelomas or plasmocytomas) appear with a high or low incidence in 2 sublines, LOU/C and LOU/M respectively, of the same inbred strain of rats. Studies of the reciprocal hybrids of the first generation between both substrains have shown that the transmission of the high tumour incidence from parents to offsprings is determined by the male as well as by the female. Absence of C-type viral particles in LOU/C rats and immunocytomas derived from them suggests that this vertical transmission might be genetically mediated.