title: Spire, an actin nucleation factor, regulates cell division during Drosophila heart development.
abstract: The Drosophila dorsal vessel is a beneficial model system for studying the regulation of early heart development. Spire (Spir), an actin-nucleation factor, regulates actin dynamics in many developmental processes, such as cell shape determination, intracellular transport, and locomotion. Through protein expression pattern analysis, we demonstrate that the absence of spir function affects cell division in Myocyte enhancer factor 2-, Tinman (Tin)-, Even-skipped- and Seven up (Svp)-positive heart cells. In addition, genetic interaction analysis shows that spir functionally interacts with Dorsocross, tin, and pannier to properly specify the cardiac fate. Furthermore, through visualization of double heterozygous embryos, we determines that spir cooperates with CycA for heart cell specification and division. Finally, when comparing the spir mutant phenotype with that of a CycA mutant, the results suggest that most Svp-positive progenitors in spir mutant embryos cannot undergo full cell division at cell cycle 15, and that Tin-positive progenitors are arrested at cell cycle 16 as double-nucleated cells. We conclude that Spir plays a crucial role in controlling dorsal vessel formation and has a function in cell division during heart tube morphogenesis.
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, United States of America. px3x@virginia.edu
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Tamara L
authors.initials: TL
authors.lastname: Johnson
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Stoller-Conrad
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schulz
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D006321:Heart / Q000196:embryology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D064326:MEF2 Transcription Factors; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D064326:MEF2 Transcription Factors; D008840:Microfilament Proteins; D018006:Myogenic Regulatory Factors; D011987:Receptors, Steroid; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C052837:eve protein, Drosophila; C109259:pnr protein, Drosophila; C402385:spir protein, Drosophila; C094295:svp protein, Drosophila; C102933:tin protein, Drosophila