RRC ID 3635
Author Takasaki T, Liu Z, Habara Y, Nishiwaki K, Nakayama J, Inoue K, Sakamoto H, Strome S.
Title MRG-1, an autosome-associated protein, silences X-linked genes and protects germline immortality in Caenorhabditis elegans.
Journal Development
Abstract MRG15, a mammalian protein related to the mortality factor MORF4, is required for cell proliferation and embryo survival. Our genetic analysis has revealed that the Caenorhabditis elegans ortholog MRG-1 serves similar roles. Maternal MRG-1 promotes embryo survival and is required for proliferation and immortality of the primordial germ cells (PGCs). As expected of a chromodomain protein, MRG-1 associates with chromatin. Unexpectedly, it is concentrated on the autosomes and not detectable on the X chromosomes. This association is not dependent on the autosome-enriched protein MES-4. Focusing on possible roles of MRG-1 in regulating gene expression, we determined that MRG-1 is required to maintain repression in the maternal germ line of transgenes on extrachromosomal arrays, and of several X-linked genes previously shown to depend on MES-4 for repression. MRG-1 is not required for PGCs to acquire transcriptional competence or for the turn-on of expression of several PGC-expressed genes (pgl-1, glh-1, glh-4 and nos-1). By contrast to this result in PGCs, MRG-1 is required for ectopic expression of those germline genes in somatic cells lacking the NuRD complex component MEP-1. We discuss how an autosome-enriched protein might repress genes on the X chromosome, promote PGC proliferation and survival, and influence the germ versus soma distinction.
Volume 134(4)
Pages 757-67
Published 2007-2
DOI 10.1242/dev.02771
PII dev.02771
PMID 17215300
PMC PMC2435364
MeSH Animals Caenorhabditis elegans / cytology Caenorhabditis elegans / genetics* Caenorhabditis elegans Proteins / physiology* Cell Proliferation Cell Survival Gene Silencing / physiology* Genes, X-Linked / genetics* Germ Cells / cytology* Repressor Proteins X Chromosome
IF 5.763
Times Cited 29
C.elegans tm1227