Invertebrate Hormones and Tumors

Hereditary, melanotic tumors in Drosophila have attracted the attention of research workers since the report of Bridges (1916) that a gene, 1(1)7, causes melanotic tumors associated with the presence of clusters of larval cells that become pigmented. Stark (1935) viewed these tumors as possibly analogous to lymphosarcoma in vertebrates. Subsequent observers (Burdette, 1959) have studied many mutant strains of these tumors that originate spontaneously and also have noted tumors sporadically in populations of Drosophila in which they are observed only on rare occasions. Both susceptibility of these strains to the tumors and their pathogenesis have been reported Three types of tumors have been encountered in Drosophila, tumorous head (tu h ) and ovarian tumors, transplanted tumors originating in l(2)gl 4 mutants, and the melanotic tumors which appear chiefly in the abdomen but may be found in the head and extremities as well.