The vascular niche controls Drosophila hematopoiesis via fibroblast growth factor signaling

  1. Manon Destalminil-Letourneau
  2. Ismaël Morin-Poulard
  3. Yushun Tian
  4. Nathalie Vanzo
  5. Michele Crozatier  Is a corresponding author
  1. Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, France
6 figures and 1 additional file

Figures

Figure 1 with 1 supplement
Lymph gland organization and RNAi screen results.

(a) Representation of lymph gland anterior and posterior lobes from third instar larvae. The anterior lobe is composed of progenitors (red) and core progenitors (hatched red), and the cortical zone …

Figure 1—source data 1

Results of the RNAi ligand screen RNAi was expressed in cardiac cells by using the handΔ-gal4 and/or NP1029-gal4 driver.

Crystal cells were labeled by BcGFP, PSC cells were immune-stained with Antp antibody, and to visualize the core progenitors tep4 in situ hybridization was performed. In most cases, 2 RNAi lines were tested per ligand, and at least 15 lymph glands per RNAi were analyzed. Crystal cell index and PSC cell number were established. The green and red colored boxes indicate an increase and a decrease, respectively, compared to the control. Black dashes indicate that no difference was observed compared to the control. A white box indicates that this condition was not tested. Most RNAi lines that gave a modification in crystal cell index with the handΔ-gal4 driver were also analyzed with another cardiac cell driver NP1029-gal4, and proPO antibody immunostainings were performed to visualize crystal cells. Finally, for all RNAi lines that led to a defect in crystal cell differentiation with the handΔ-gal4 driver, tep4 in situ hybridizations were performed and the tep4 index was established.

https://cdn.elifesciences.org/articles/64672/elife-64672-fig1-data1-v1.xlsx
Figure 1—source data 2

Results of the RNAi ligand screen.

https://cdn.elifesciences.org/articles/64672/elife-64672-fig1-data2-v1.xlsx
Figure 1—figure supplement 1
Expression pattern of handΔ-gal4 and NP1029-gal4 driver in lymph glands during larval development.

(a–c’) HandΔ-gal4 > mcd8 GFP is green in (a–c) and white in (a’–c’). (d–f’) NP1029-gal4 > mcd8 GFP is green in (d–f) and white in (d’–f’). The PSC is labeled by Col (red and arrow in a); thin and …

Figure 2 with 2 supplements
Ligand Bnl is expressed in cardiac cells and controls lymph gland homeostasis.

(a) A maximum projection of 5 confocal lymph gland sections, bnl (red) is expressed in cardiac cells and MZ progenitors that express domeMESO-GFP (green). (a’, a’’) An enlarged view, bnl is red (a’) …

Figure 2—figure supplement 1
The ligand Bnl in cardiac cells controls lymph gland hemocyte differentiation homeostasis.

(a–c”) A maximum projection of 5 confocal lymph gland sections, bnl is in red. (a,b,c) and white in (a”,b”,c”). BcGFP (green) labels crystal cells. (a’–a”) An enlarged view, crystal cells are green …

Figure 2—figure supplement 2
Whereas the ligand Bnl in cardiac cells does not control PSC cells, it is required in MZ progenitors to regulate lymph gland homeostasis.

(a, b) Crystal cells are labeled by proPO antibody (green). An increase in crystal cell number is observed when bnl expression is decreased in MZ progenitors (b) compared to the control (a). (c) …

Figure 3 with 1 supplement
Receptor Btl is expressed in hematopoietic progenitors and required to control lymph gland homeostasis.

(a) A maximum projection of 5 confocal lymph gland sections of larvae expressing btl:cherryendo (red) and domeMESO-GFP that labels MZ progenitors (green). (a’, a’’) An enlarged view, btl:cherryendo

Figure 3—figure supplement 1
The Btl receptor in progenitors controls lymph gland hemocyte differentiation without affecting PSC size.

(a–c”) A maximum projection of 5 confocal lymph gland sections of larvae expressing btl:cherryendo (red). (a–a’) BcGFP (green) labels crystal cells. (a’–a”) An enlarged view, crystal cells are green …

Figure 4 with 1 supplement
Ligand Bnl secreted by cardiac cells controls lymph gland crystal cell differentiation.

(a) Active bnl::GFP fusion protein is expressed in cardiac cells using handΔ-gal4 driver. Dashed lines indicate cardiac tube and the PSC is labeled by Collier (Col, red and red arrow). (a’, a’’) An …

Figure 4—figure supplement 1
Knocking down sar1 in cardiac cells impairs crystal cell differentiation and increases PSC size.

(a–b, d–e) PSC cells are labeled with Antp (green) antibody. An increase in PSC cell numbers is observed when sar1 is knocked down in cardiac cells using the handΔ driver (b) compared to the control …

Figure 5 with 1 supplement
Btl receptor interacts genetically with CamKII to control blood cell differentiation by preventing high Ca2+ levels in progenitors.

(a, b) GCaMP3 Ca2+ sensor (dome >UAS-GCaMP3) is white. GCaMP3 intensity decreases when btl is knocked down in MZ progenitors (b) compared to the control (a). (c) Quantification of GCaMP3 intensity. …

Figure 5—figure supplement 1
Ca2+ levels in progenitors regulate crystal cell differentiation.

(a, b) L2 larval lymph glands and the GCaMP3 Ca2+ sensor (dome >UAS-GCaMP3) is white. No difference observed in GCaMP3 intensity between the control (a) and when btl is knocked down in MZ …

Two niches control lymph gland homeostasis.

(a–b) Schematic representation of third instar larvae lymph gland anterior lobes. Progenitors and core progenitors are in red and hatched red, respectively. The cortical zone (CZ) is in green, the …

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