Germ-line induction of the Caenorhabditis elegans vulva.
Development of the Caenorhabditis elegans vulva serves as a paradigm for intercellular signaling during animal development. In wild-type animals, the somatic gonadal anchor cell generates the LIN-3/EGF ligand to induce vulval fates in the underlying hypodermis, whereas FBF, FOG-1, and FOG-3 control germ-line development. Here we report that FBF functions redundantly with FOG-1 and FOG-3 to control vulval induction: animals lacking FBF and either FOG-1 or FOG-3 have multiple vulvae, the Muv phenotype. The fog; fbf Muv phenotype is generated by aberrant induction of vulval precursor cells (VPCs): in wild-type animals, three VPCs are induced to form a single vulva, but, in fog; fbf mutants, four or five VPCs are typically induced, resulting in ectopic vulvae. Laser ablation experiments and mosaic analyses demonstrate that the germ line is critical for the fog; fbf Muv phenotype. Consistent with that site of action, we detect FBF and FOG-1 in the germ line but not in the VPCs. The simplest interpretation is that FOG-1, FOG-3, and FBF act in the germ line to influence vulval fates. The LIN-3/EGF ligand may be the germ-line signal to the VPCs: the fog; fbf Muv phenotype depends on LIN-3 activity, and the lin-3 3' UTR possesses an FBF binding element. Our findings reveal new insights into germ line-to-soma signals and the role of PUF proteins in animal development.
Thompson
Beth E
BE
Cellular and Molecular Biology Program, Department of Biochemistry, and Howard Hughes Medical Institute, University of Wisconsin, 433 Babcock Drive, Madison, WI 53706, USA.
Lamont
Liana B
LB
Kimble
Judith
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015536:Down-Regulation / Q000235:genetics; D004627:Embryonic Induction / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D009030:Mosaicism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D014844:Vulva / Q000196:embryology*
D029742:Caenorhabditis elegans Proteins; C403465:FOG-3 protein, C elegans; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C109286:fem-3-binding protein, C elegans; C498431:fog-1 protein, C elegans; C075912:Lin-3 protein, C elegans; D004815:Epidermal Growth Factor