Telomeric position effect variegation in Saccharomyces cerevisiae by Caenorhabditis elegans linker histones suggests a mechanistic connection between germ line and telomeric silencing.
Linker histones are nonessential for the life of single-celled eukaryotes. Linker histones, however, can be important components of specific developmental programs in multicellular animals and plants. For Caenorhabditis elegans a single linker histone variant (H1.1) is essential in a chromatin silencing process which is crucial for the proliferation and differentiation of the hermaphrodite germ line. In this study we analyzed the whole linker histone complement of C. elegans by telomeric position effect variegation in budding yeast. In this assay an indicator gene (URA3) placed close to the repressive telomeric chromatin structure is subject to epigenetically inherited gene inactivation. Just one out of seven C. elegans linker histones (H1.1) was able to enhance the telomeric position effect in budding yeast. Since these results reflect the biological function of H1.1 in C. elegans, we suggest that chromatin silencing in C. elegans is governed by molecular mechanisms related to the telomere-dependent silencing in budding yeast. We confirmed this hypothesis by testing C. elegans homologs of three yeast genes which are established modifiers of the yeast telomeric chromatin structure (SIR2, SET1, and RAD17) for their influence on repeat-dependent transgene silencing for C. elegans.
Georg-August University of Göttingen, Third Department of Zoology-Developmental Biology, Humboldtallee 34A, D-37073 Göttingen, Germany.
Monika A
MA
Jedrusik
Ekkehard
E
Schulze
D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D020868:Gene Silencing; D049452:Green Fluorescent Proteins; D006657:Histones / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D008164:Luminescent Proteins / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D010802:Phylogeny; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D034622:RNA Interference; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012984:Software; D016615:Telomere
D002843:Chromatin; D006657:Histones; D006877:Hydroxamic Acids; D008164:Luminescent Proteins; D010455:Peptides; D011500:Protein Synthesis Inhibitors; D049452:Green Fluorescent Proteins; C012589:trichostatin A; D004247:DNA