biostudies-literatureWan HNatural Sciences and Engineering Research Council of CanadaUniversity of Torontodev204843https://www.ebi.ac.uk/biostudies/studies/S-EPMC12912265biostudies-literatureUnknown153(3)In zebrafish, epiboly is a major morphogenic event during gastrulation, characterized by the thinning and spreading of the embryonic blastoderm to internalize the underlying extra-embryonic yolk cell. This movement is driven by the yolk cell, which generates motile force through actomyosin flow that engages a circumferential contractile band, pulling the attached blastoderm vegetally. Localized macropinocytosis of the yolk cell, another actin-driven process, also contributes to epiboly progression by removing yolk membrane ahead of the advancing blastoderm. The molecular mechanisms coordinating these processes are elusive. Here, we identified Camsap2a, a non-centrosomal, microtubule-stabilizing protein, as a regulator of actin-dependent processes in the yolk cell during epiboly. Epiboly isDevelopment (Cambridge, England)Camsap2a regulates actomyosin flow and Rab5ab-mediated macropinocytosis in the yolk cell during zebrafish epiboly.PMC12912265458019201009Quibria SIu EUser SDBruce AEEWan HPlotnikov SVfalseCamsap2a regulates actomyosin flow and Rab5ab-mediated macropinocytosis in the yolk cell during zebrafish epiboly.In zebrafish, epiboly is a major morphogenic event during gastrulation, characterized by the thinning and spreading of the embryonic blastoderm to internalize the underlying extra-embryonic yolk cell. This movement is driven by the yolk cell, which generates motile force through actomyosin flow that engages a circumferential contractile band, pulling the attached blastoderm vegetally. Localized macropinocytosis of the yolk cell, another actin-driven process, also contributes to epiboly progression by removing yolk membrane ahead of the advancing blastoderm. The molecular mechanisms coordinating these processes are elusive. Here, we identified Camsap2a, a non-centrosomal, microtubule-stabilizing protein, as a regulator of actin-dependent processes in the yolk cell during epiboly. Epiboly is2026-01-01T00:00:00Z2026 Feb2026-07-16T00:38:21.481Z2026-07-09T10:26:26.435ZS-EPMC129122654162745210.1242/dev.204843