title: MEG-1 and MEG-2 are embryo-specific P-granule components required for germline development in Caenorhabditis elegans.
abstract: In Caenorhabditis elegans, germ granules called P granules are directly inherited from mother to daughter and segregate with the germ lineage as it separates from the soma during initial embryonic cell divisions. Here we define meg-1 and meg-2 (maternal-effect germ-cell defective), which are expressed in the maternal germline and encode proteins that localize exclusively to P granules during embryonic germline segregation. Localization of MEG-1 to P granules depends upon the membrane-bound protein MES-1. meg-1 mutants exhibit multiple germline defects: P-granule mis-segregation in embryos, underproliferation and aberrant P-granule morphology in larval germ cells, and ultimately, sterility as adults. The penetrance of meg-1 phenotypes increases when meg-2 is also absent. Loss of the P-granule component pgl-1 in meg-1 mutants increases germ-cell proliferation, while loss of glh-1 decreases proliferation. Because meg-1 is provided maternally but its action is required in the embryonic germ lineage during segregation from somatic lineages, it provides a critical link for ensuring the continuity of germline development from one generation to the next.
authors.affiliation: Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: Stefanie W
authors.initials: SW
authors.lastname: Leacock
authors.forename: Valerie
authors.initials: V
authors.lastname: Reinke
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D002470:Cell Survival; D003594:Cytoplasmic Granules / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism*; D005298:Fertility; D017238:Genes, Helminth; D005854:Germ Cells / Q000166:cytology / Q000254:growth & development*; D007814:Larva / Q000166:cytology; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013696:Temperature
chemical_list: D029742:Caenorhabditis elegans Proteins; D011993:Recombinant Fusion Proteins