The vascular niche controls Drosophila hematopoiesis via fibroblast growth factor signaling

• Published in: eLife Vol. 10; no. 21; pp. 9269 - 9282
• Main Authors: Destalminil-Letourneau, Manon, Morin-Poulard, Ismaël, Tian, Yushun, Vanzo, Nathalie, Crozatier, Michele
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 04.01.2021; eLife Sciences Publications Ltd; eLife Sciences Publication; eLife Sciences Publications, Ltd
• Subjects: Animals; Blood; Blood cells; Bone marrow; Calcium (intracellular); Calcium signalling; cardiac/vascular cells; Cell differentiation; Development Biology; Developmental Biology; Drosophila; Drosophila - physiology; FGF signaling; Fibroblast growth factors; Fibroblast Growth Factors - metabolism; Fibroblasts; Genetics; Genotype & phenotype; Growth factors; hematopoiesis; Hematopoiesis - physiology; Hematopoietic stem cells; Homeostasis; Insects; Intracellular signalling; Life Sciences; Ligands; Lymph; Lymph gland; Mammals; microenvironment/niche; Microenvironments; Progenitor cells; Signal Transduction; Vascular system; hematopoiesis; lymph gland; microenvironment/niche; Drosophila; FGF signaling; developmental biology; D. melanogaster; cardiac/vascular cells
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.64672

In adult mammals, hematopoiesis, the production of blood cells from hematopoietic stem and progenitor cells (HSPCs), is tightly regulated by extrinsic signals from the microenvironment called 'niche'. Bone marrow HSPCs are heterogeneous and controlled by both endosteal and vascular niches. The Drosophila hematopoietic lymph gland is located along the cardiac tube which corresponds to the vascular system. In the lymph gland, the niche called Posterior Signaling Center controls only a subset of the heterogeneous hematopoietic progenitor population indicating that additional signals are necessary. Here we report that the vascular system acts as a second niche to control lymph gland homeostasis. The FGF ligand Branchless produced by vascular cells activates the FGF pathway in hematopoietic progenitors. By regulating intracellular calcium levels, FGF signaling maintains progenitor pools and prevents blood cell differentiation. This study reveals that two niches contribute to the control Drosophila blood cell homeostasis through their differential regulation of progenitors.