Ultrastructure and Cytochemistry of the Cell-types in the Tumorous Hematopoietic Organs and the Hemolymph of the Mutant Lethal (1) Malignant Blood Neoplasm (l(1)mbn) of Drosophila Melanogaster

The fine structure and histochemistry of the neoplastic primordial blood cell-types in the larval hematopoietic organs and the mature cell-types in the hemolymph of the blood tumor mutant lethal (1) malignant blood neoplasm (l(1) mbn ) of Drosophila melanogaster were investigated. In this mutant the cell-types of the plasmatocyte-line are neoplastic while the cell-types of the crystal-cell-line are not and are much reduced in numbers (1, 2).
In contrast to the wild-type the mutant hematopoietic organs are enlarged and contain, in addition to primordial blood-cells, large numbers of mature plasmato-, podo-, and lamellocytes.
All cell-types of the plasmatocyte-line differ in their fine structure and behavior from their wild-type counterparts. The mutant blood cells show generally a numerical increase of cell organelles and acid phosphatase positive primary and secondary lysosomes. In the phenol oxidase test they showed a vigorous melanization reaction. Plasmato- and podocytes invade into the tissues of the larva and show high phagocytic activity.