Fascin is required for blood cell migration during Drosophila embryogenesis.
Fascin is well characterized in vitro as an actin-bundling protein and its increased expression is correlated with the invasiveness of various cancers. However, the actual roles and regulation of Fascin in vivo remain elusive. Here we show that Fascin is required for the invasive-like migration of blood cells in Drosophila embryos. Fascin expression is highly regulated during embryonic development and, within the blood lineage, is specific to the motile subpopulation of cells, which comprises macrophage-like plasmatocytes. We show that Fascin is required for plasmatocyte migration, both as these cells undergo developmental dispersal and during an inflammatory response to epithelial wounding. Live analyses further demonstrate that Fascin localizes to, and is essential for the assembly of, dynamic actin-rich microspikes within plasmatocyte lamellae that polarize towards the direction of migration. We show that a regulatory serine of Fascin identified from in vitro studies is not required for in vivo cell motility, but is crucial for the formation of actin bundles within epithelial bristles. Together, these results offer a first glimpse into the mechanisms regulating Fascin function during normal development, which might be relevant for understanding the impact of Fascin in cancers.
Zanet
Jennifer
J
Université de Toulouse, UPS, Centre de Biologie du Développement, Bâtiment 4R3, Toulouse, France.
Stramer
Brian
B
Millard
Thomas
T
Martin
Paul
P
Payre
François
F
Plaza
Serge
S
D000595:Amino Acid Sequence; D000825:Animal Structures / Q000196:embryology / Q000648:ultrastructure; D000818:Animals; D001773:Blood Cells / Q000166:cytology* / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement; D016764:Cell Polarity; D002470:Cell Survival; D003599:Cytoskeleton / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology* / Q000235:genetics / Q000648:ultrastructure; D047108:Embryonic Development / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation / Q000235:genetics; D009866:Oogenesis; D009928:Organ Specificity; D010766:Phosphorylation; D011554:Pseudopodia / Q000378:metabolism; D012694:Serine / Q000378:metabolism
D002352:Carrier Proteins; D008840:Microfilament Proteins; C020324:fascin; D012694:Serine