Notch Signaling Controls Lineage Specification during Drosophila Larval Hematopoiesis  Bernard Duvic, Jules A Hoffmann, Marie Meister, Julien Royet  Current Biology  Volume 12, Issue 22, Pages 1923-1927 (November 2002) DOI: 10.1016/S0960-9822(02)01297-6

Figure 1 Hemocytes in Larvae Mutant for the Notch Signaling Pathway (A–F) Larvae of various genotypes were heated to 60°C for 10 min, a process that provokes blackening of mature crystal cells, which are subsequently easily visualized through the cuticle. (A) Crystal cell numbers in the last two posterior segments of third instar larvae of the indicated genotype. Loss-of-fonction mutations in Notch pathway components lead to a reduction of the number of crystal cells. Gain-of-function mutations give rise to the opposite phenotype. A total of 5–14 larvae were analyzed per genotype. A single asterisk indicates that results are not significantly different from wild-type control; a double asterisk indicates that results are significantly different from wild-type control (p < 0.05). (B–F) Posterior part of third instar larvae of the following genotypes: OregonR (+), Nts1 after 3 days at 29°C, hsp-Gal4/UAS-Nic, hsp-Gal4/UAS-Ser, and Dx1. The scale bar represents 100 μm. (G) Plasmatocyte numbers in third instar larvae. Note that the values are strongly dependent on the genetic background, and mutant cell numbers must be compared to those of heterozygous siblings. Current Biology 2002 12, 1923-1927DOI: (10.1016/S0960-9822(02)01297-6)

Figure 2 Expression of Prophenoloxidase in Larval Lymph Glands (A–F) Immunolocalization of proPO is shown in red. Third instar larvae lymph glands from (A) Nts1 raised at 18°C, (B) Nts1 raised at 29°C, (C) Su(H)SF8/Su(H)HG36, (D) NMcd8, (E) hsp-Gal4/UAS-Nic, or (F) e33C/UAS-Ser were stained with a rat anti-proPO antibody. Arrows point to proPO-positive cells. (G) Detail of the anterior region of a heated e33C-Gal4/UAS-Ser larva in which the lymph glands are visible; lymph glands contain many blackened crystal cells within the anteriormost lobes. The scale bar represents 50 μm. Current Biology 2002 12, 1923-1927DOI: (10.1016/S0960-9822(02)01297-6)

Figure 3 Effect of N Mutation on Serpent Expression in Larval Lymph Glands (A and B) Nts1 larvae raised at (A) permissive or (B) restrictive temperature were stained with an anti-Serpent antibody. The scale bar represents 50 μm. Current Biology 2002 12, 1923-1927DOI: (10.1016/S0960-9822(02)01297-6)

Figure 4 Effect of Notch Signaling on Lamellocyte Differentiation (A and B) Nts1 second instar larvae raised at (A) permissive or (B) restrictive temperature were infected with Leptopilina boulardi and dissected 72 and 48 hr, respectively, after wasp infection. Blood cells were visualized through DAPI staining of hemolymph drops. In the absence of N function, the production of lamellocytes (inset in [A]) is strongly reduced, although not abolished. Mostly plasmatocytes are observed in the circulating blood (inset in [B]). (C) Molecular regulation of hemocyte differentiation in Drosophila larvae. srp is expressed in all precursor cells. Plasmatocyte differentiation requires gcm function; crystal cell specification is controlled by the Notch signaling pathway, by lz, and by ush; and lamellocyte production also requires N function and is affected by the Toll and the JAK/STAT signaling pathways [20, 21]. The scale bar represents 50 μm. Current Biology 2002 12, 1923-1927DOI: (10.1016/S0960-9822(02)01297-6)