Early morphogenesis of the Caenorhabditis elegans pharynx.
We investigated the cellular behaviors that accompany the early stages of pharyngeal morphogenesis in Caenorhabditis elegans. The embryonic pharynx develops from a ball of cells into a linear tube connected anteriorly to the buccal cavity and posteriorly to the midgut. By using GFP reporters localized to discrete subcellular regions, we show that pharyngeal morphogenesis can be divided into three stages: (1) lengthening of the nascent pharyngeal lumen by reorientation of apicobasal polarity of anterior pharyngeal cells ("Reorientation"), (2) formation of an epithelium by the buccal cavity cells, which mechanically couples the buccal cavity to the pharynx and anterior epidermis ("Epithelialization"), and (3) a concomitant movement of the pharynx anteriorly and the epidermis of the mouth posteriorly to bring the pharynx, buccal cavity, and mouth into close apposition ("Contraction"). Several models can account for these cellular behaviors, and we distinguish between them by physically or genetically ablating cells within the digestive tract. These studies provide the first description of how the pharynx primordium develops into an epithelial tube, and reveal that pharyngeal morphogenesis resembles aspects of mammalian kidney tubulogenesis.
Portereiko
M F
MF
Department of Oncological Sciences, University of Utah, 2000 Circle of Hope, Salt Lake City, Utah 84112, USA.
Mango
S E
SE
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019521:Body Patterning; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D049452:Green Fluorescent Proteins; D007668:Kidney / Q000196:embryology; D008164:Luminescent Proteins / Q000235:genetics; D008954:Models, Biological; D010614:Pharynx / Q000196:embryology*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D015398:Signal Transduction
D017931:DNA Primers; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins