title: Analysis of PHA-1 reveals a limited role in pharyngeal development and novel functions in other tissues.
abstract: PHA-1 encodes a cytoplasmic protein that is required for embryonic morphogenesis and attachment of the foregut (pharynx) to the mouth (buccal capsule). Previous reports have in some cases suggested that PHA-1 is essential for the differentiation of most or all pharyngeal cell types. By performing mosaic analysis with a recently acquired pha-1 null mutation (tm3671), we found that PHA-1 is not required within most or all pharyngeal cells for their proper specification, differentiation, or function. Rather, our evidence suggests that PHA-1 acts in the arcade or anterior epithelial cells of the pharynx to promote attachment of the pharynx to the future buccal capsule. In addition, PHA-1 appears to be required in the epidermis for embryonic morphogenesis, in the excretory system for osmoregulation, and in the somatic gonad for normal ovulation and fertility. PHA-1 activity is also required within at least a subset of intestinal cells for viability. To better understand the role of PHA-1 in the epidermis, we analyzed several apical junction markers in pha-1(tm3671) homozygous embryos. PHA-1 regulates the expression of several components of two apical junction complexes including AJM-1-DLG-1/discs large complex and the classical cadherin-catenin complex, which may account for the role of PHA-1 in embryonic morphogenesis.
authors.affiliation: Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming 82071.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Kuzmanov
authors.affiliation: Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming 82071.
authors.forename: John
authors.initials: J
authors.lastname: Yochem
authors.affiliation: Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming 82071 davidfay@uwyo.edu.
authors.forename: David S
authors.initials: DS
authors.lastname: Fay
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D051177:Catenins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D051528:Guanylate Kinases / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010614:Pharynx / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D019108:Tight Junctions / Q000378:metabolism
chemical_list: C441580:AJM-1 protein, C elegans; D015820:Cadherins; D029742:Caenorhabditis elegans Proteins; D051177:Catenins; C489033:PHA-1 protein, C elegans; C530790:DLG-1 protein, C elegans; D051528:Guanylate Kinases
keywords: C. elegans; apical junctions; epithelium; morphogenesis; mosaic analysis; pha-1; pharynx