The Polycomb group in Caenorhabditis elegans and maternal control of germline development.
Four Caenorhabditis elegans genes, mes-2, mes-3, mes-4 and mes-6, are essential for normal proliferation and viability of the germline. Mutations in these genes cause a maternal-effect sterile (i.e. mes) or grandchildless phenotype. We report that the mes-6 gene is in an unusual operon, the second example of this type of operon in C. elegans, and encodes the nematode homolog of Extra sex combs, a WD-40 protein in the Polycomb group in Drosophila. mes-2 encodes another Polycomb group protein (see paper by Holdeman, R., Nehrt, S. and Strome, S. (1998). Development 125, 2457-2467). Consistent with the known role of Polycomb group proteins in regulating gene expression, MES-6 is a nuclear protein. It is enriched in the germline of larvae and adults and is present in all nuclei of early embryos. Molecular epistasis results predict that the MES proteins, like Polycomb group proteins in Drosophila, function as a complex to regulate gene expression. Database searches reveal that there are considerably fewer Polycomb group genes in C. elegans than in Drosophila or vertebrates, and our studies suggest that their primary function is in controlling gene expression in the germline and ensuring the survival and proliferation of that tissue.
Korf
I
I
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Fan
Y
Y
Strome
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins; D002455:Cell Division; D002470:Cell Survival; D012734:Disorders of Sex Development; D004330:Drosophila; D029721:Drosophila Proteins; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000096:biosynthesis / Q000737:chemistry; D011495:Histone-Lysine N-Methyltransferase; D019476:Insect Proteins / Q000737:chemistry / Q000502:physiology; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000737:chemistry; D016366:Open Reading Frames; D063150:Polycomb Repressive Complex 1; D063151:Polycomb Repressive Complex 2; D063146:Polycomb-Group Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; D029721:Drosophila Proteins; D015801:Helminth Proteins; D019476:Insect Proteins; D009687:Nuclear Proteins; C066770:Pc protein, Drosophila; D063146:Polycomb-Group Proteins; C113415:mes-6 protein, C elegans; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2; C543389:esc protein, Drosophila; D063150:Polycomb Repressive Complex 1