Figure 1 .

Schematic representation of the lymph gland structure. (A) Whole lymph gland with primary and secondary lobes. (B–C) Cross-sections and z-sections of normal primary lobe of middle (B) and late (C) third-instar larval lymph glands. MZ prohemocytes expressing dome-GAL4 are shown in green. Prohemocytes expressing no markers are blue. CZ prohemocytes expressing Pxn are shown in yellow, crystal cells are purple, and lamellocytes are elongated red cells. Plasmatocytes (encircled in red) first differentiate at the surface of the CZ. (D, E) Primary lobes disintegrate upon metamorphosis or in response to immune challenge. Disintegration is also observed in a number of mutants as a result of accelerated hemocyte differentiation. (F, G) Examples of abnormally shaped primary lobes observed during the screen. Markers and their expression used in this study are indicated below the drawing.