Embryonic morphogenesis in Caenorhabditis elegans integrates the activity of LET-502 Rho-binding kinase, MEL-11 myosin phosphatase, DAF-2 insulin receptor and FEM-2 PP2c phosphatase.
let-502 rho-binding kinase and mel-11 myosin phosphatase regulate Caenorhabditis elegans embryonic morphogenesis. Genetic analysis presented here establishes the following modes of let-502 action: (i) loss of only maternal let-502 results in abnormal early cleavages, (ii) loss of both zygotic and maternal let-502 causes elongation defects, and (iii) loss of only zygotic let-502 results in sterility. The morphogenetic function of let-502 and mel-11 is apparently redundant with another pathway since elimination of these two genes resulted in progeny that underwent near-normal elongation. Triple mutant analysis indicated that unc-73 (Rho/Rac guanine exchange factor) and mlc-4 (myosin light chain) act in parallel to or downstream of let-502/mel-11. In contrast mig-2 (Rho/Rac), daf-2 (insulin receptor), and age-1 (PI3 kinase) act within the let-502/mel-11 pathway. Mutations in the sex-determination gene fem-2, which encodes a PP2c phosphatase (unrelated to the MEL-11 phosphatase), enhanced mutations of let-502 and suppressed those of mel-11. fem-2's elongation function appears to be independent of its role in sexual identity since the sex-determination genes fem-1, fem-3, tra-1, and tra-3 had no effect on mel-11 or let-502. By itself, fem-2 affects morphogenesis with low penetrance. fem-2 blocked the near-normal elongation of let-502; mel-11 indicating that fem-2 acts in a parallel elongation pathway. The action of two redundant pathways likely ensures accurate elongation of the C. elegans embryo.
Piekny
A J
AJ
Genes & Development Research Group and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
Wissmann
A
A
Mains
P E
PE
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000201:enzymology / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D003285:Contractile Proteins / Q000235:genetics / Q000502:physiology; D012734:Disorders of Sex Development; D004625:Embryo, Nonmammalian / Q000201:enzymology; D005298:Fertility; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009024:Morphogenesis; D043263:Myosin-Light-Chain Phosphatase; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D011972:Receptor, Insulin / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019849:Sex Determination Processes; D054460:rho-Associated Kinases
D029742:Caenorhabditis elegans Proteins; D003285:Contractile Proteins; D015801:Helminth Proteins; D047908:Intracellular Signaling Peptides and Proteins; C107483:DAF-2 protein, C elegans; D011972:Receptor, Insulin; C515856:LET-502 protein, C elegans; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C097435:Fem-2 protein, C elegans; D010749:Phosphoprotein Phosphatases; D043263:Myosin-Light-Chain Phosphatase