title: The gelsolin-related flightless I protein is required for actin distribution during cellularisation in Drosophila.
abstract: We have analysed the developmental defects in Drosophila embryos lacking a gelsolin-related protein encoded by the gene flightless I. Such embryos have previously been reported to gastrulate abnormally. We now show that the most dramatic defects are seen earlier, in actin-dependent events during cellularisation of the syncytial blastoderm, a process with similarities to cytokinesis. The blastoderm nuclei migrate to the periphery of the egg normally but lose their precise cortical positioning during cellularisation. Cleavage membranes are initially formed, but invaginate irregularly and often fail to close at the basal end of the newly formed cells. The association of actin with the cellularisation membranes is irregular, suggesting a role for flightless I in the delivery of actin to the actin network, or in its stabilisation.
authors.affiliation: Max Planck Institut für Entwicklungsbiologie, Tübingen, Germany.
authors.forename: K L
authors.initials: KL
authors.lastname: Straub
authors.forename: M C
authors.initials: MC
authors.lastname: Stella
authors.forename: M
authors.initials: M
authors.lastname: Leptin
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002455:Cell Division; D003599:Cytoskeleton / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000254:growth & development; D029721:Drosophila Proteins; D005775:Gastrula; D018260:Gelsolin; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D009154:Mutation; D011506:Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D000199:Actins; D029721:Drosophila Proteins; D018260:Gelsolin; D011506:Proteins; C098178:fliI protein, Drosophila