Distinct mechanisms regulate hemocyte chemotaxis during development and wound healing in Drosophila melanogaster.
Drosophila melanogaster hemocytes are highly motile macrophage-like cells that undergo a stereotypic pattern of migration to populate the whole embryo by late embryogenesis. We demonstrate that the migratory patterns of hemocytes at the embryonic ventral midline are orchestrated by chemotactic signals from the PDGF/VEGF ligands Pvf2 and -3 and that these directed migrations occur independently of phosphoinositide 3-kinase (PI3K) signaling. In contrast, using both laser ablation and a novel wounding assay that allows localized treatment with inhibitory drugs, we show that PI3K is essential for hemocyte chemotaxis toward wounds and that Pvf signals and PDGF/VEGF receptor expression are not required for this rapid chemotactic response. Our results demonstrate that at least two separate mechanisms operate in D. melanogaster embryos to direct hemocyte migration and show that although PI3K is crucial for hemocytes to sense a chemotactic gradient from a wound, it is not required to sense the growth factor signals that coordinate their developmental migrations along the ventral midline during embryogenesis.
Wood
Will
W
Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
Faria
Celia
C
Jacinto
Antonio
A
D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002633:Chemotaxis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002867:Chromones / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000502:physiology*; D004527:Egg Proteins / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D006434:Hemocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D017403:In Situ Hybridization; D008856:Microscopy, Fluorescence; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D000081082:Phosphoinositide-3 Kinase Inhibitors; D034741:RNA, Small Interfering / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D013997:Time Factors
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002867:Chromones; D015638:Cytochalasin D; D029721:Drosophila Proteins; D004527:Egg Proteins; D004791:Enzyme Inhibitors; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D034741:RNA, Small Interfering; D020794:Receptor Protein-Tyrosine Kinases; D013844:Thiazoles; D053778:Thiazolidines; C487426:PVF3 protein, Drosophila; C438367:Pvf1 protein, Drosophila; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C438368:Pvr protein, Drosophila; C037068:latrunculin B