Hyperactivation of the folded gastrulation pathway induces specific cell shape changes

Pierre Morize, Audrey E. Christiansen, Mike Costa, Suki Parks, Eric Wieschaus

Research output: Contribution to journalArticle

69 Scopus citations

Abstract

During Drosophila gastrulation, mesodermal precursors are brought into the interior of the embryo by formation of the ventral furrow. The first steps of ventral furrow formation involve a flattening of the apical surface of the presumptive mesodermal cells and a constriction of their apical diameters. In embryos mutant for folded gastrulation (fog), these cell shape changes occur but the timing and synchrony of the constrictions are abnormal. A similar phenotype is seen in a maternal effect mutant, concertina (cta), fog encodes a putative secreted protein whereas cta encodes an α-subunit of a heterotrimeric G protein. We have proposed that localized expression of the fog signaling protein induces apical constriction by interacting with a receptor whose downstream cellular effects are mediated by the cta Gα protein. In order to test this model, we have ectopically expressed fog at the blastoderm stage using an inducible promoter. In addition, we have examined the constitutive activation of cta protein by blocking GTP hydrolysis using both in vitro synthesized mutant alleles and cholera toxin treatment. Activation of the fog/cta pathway by any of these procedures results in ectopic cell shape changes in the gastrula. Uniform fog expression rescues the gastrulation defects of fog null embryos but not cta mutant embryos, arguing that cta functions downstream of fog expression. The normal location of the ventral furrow in embryos with uniformly expressed fog suggests the existence of a fog-independent pathway determining mesoderm-specific cell behaviors and invagination. Epistasis experiments indicate that this pathway requires snail but not twist expression.

Original languageEnglish (US)
Pages (from-to)589-597
Number of pages9
JournalDevelopment
Volume125
Issue number4
StatePublished - Feb 1 1998

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Developmental Biology

Keywords

  • Drosophila
  • Gastrulation
  • Invagination
  • Morphogenesis
  • concertina
  • folded gastrulation

Fingerprint Dive into the research topics of 'Hyperactivation of the folded gastrulation pathway induces specific cell shape changes'. Together they form a unique fingerprint.

Cite this