title: Developmentally restricted actin-regulatory molecules control morphogenetic cell movements in the zebrafish gastrula.
abstract: Although our understanding of the regulation of cellular actin and its control during the development of invertebrates is increasing, the question as to how such actin dynamics are regulated differentially across the vertebrate embryo to effect its relatively complex morphogenetic cell movements remains poorly understood. Intercellular signaling that provides spatial and temporal cues to modulate the subcellular localization and activity of actin regulatory molecules represents one important mechanism. Here we explore whether the localized gene expression of specific actin regulatory molecules represents another developmental mechanism. We have identified a cap1 homolog and a novel guanine nucleotide exchange factor (GEF), quattro (quo), that share a restricted gene expression domain in the anterior mesendoderm of the zebrafish gastrula. Each gene is required for specific cellular behaviors during the anterior migration of this tissue; furthermore, cap1 regulates cortical actin distribution specifically in these cells. Finally, although cap1 and quo are autonomously required for the normal behaviors of these cells, they are also nonautonomously required for convergence and extension movements of posterior tissues. Our results provide direct evidence for the deployment of developmentally restricted actin-regulatory molecules in the control of morphogenetic cell movements during vertebrate development.
authors.affiliation: Comparative and Developmental Genetics Section, Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh EH4 2XU, United Kingdom. ddaggett@berkeley.edu
authors.forename: David F
authors.initials: DF
authors.lastname: Daggett
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Boyd
authors.forename: Philippe
authors.initials: P
authors.lastname: Gautier
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Bryson-Richardson
authors.forename: Christine
authors.initials: C
authors.lastname: Thisse
authors.forename: Bernard
authors.initials: B
authors.lastname: Thisse
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Amacher
authors.forename: Peter D
authors.initials: PD
authors.lastname: Currie
mesh_terms: D000199:Actins / Q000378:metabolism* / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology*; D018076:DNA, Complementary / Q000235:genetics; D030541:Databases, Genetic; D005656:Fungal Proteins; D005775:Gastrula / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009024:Morphogenesis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: C412447:AP1 protein, Candida albicans; D000199:Actins; D050976:Basic-Leucine Zipper Transcription Factors; C525387:Cap1 protein, zebrafish; D002352:Carrier Proteins; D018076:DNA, Complementary; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D014157:Transcription Factors; D029961:Zebrafish Proteins; C495877:quo protein, zebrafish