title: The linker histone plays a dual role during gametogenesis in Saccharomyces cerevisiae.
abstract: The differentiation of gametes involves dramatic changes to chromatin, affecting transcription, meiosis, and cell morphology. Sporulation in Saccharomyces cerevisiae shares many chromatin features with spermatogenesis, including a 10-fold compaction of the nucleus. To identify new proteins involved in spore nuclear organization, we purified chromatin from mature spores and discovered a significant enrichment of the linker histone (Hho1). The function of Hho1 has proven to be elusive during vegetative growth, but here we demonstrate its requirement for efficient sporulation and full compaction of the spore genome. Hho1 chromatin immunoprecipitation followed by sequencing (ChIP-seq) revealed increased genome-wide binding in mature spores and provides novel in vivo evidence of the linker histone binding to nucleosomal linker DNA. We also link Hho1 function to the transcription factor Ume6, the master repressor of early meiotic genes. Hho1 and Ume6 are depleted during meiosis, and analysis of published ChIP-chip data obtained during vegetative growth reveals a high binding correlation of both proteins at promoters of early meiotic genes. Moreover, Ume6 promotes binding of Hho1 to meiotic gene promoters. Thus, Hho1 may play a dual role during sporulation: Hho1 and Ume6 depletion facilitates the onset of meiosis via activation of Ume6-repressed early meiotic genes, whereas Hho1 enrichment in mature spores contributes to spore genome compaction.
authors.affiliation: Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Bryant
authors.forename: Jérôme
authors.initials: J
authors.lastname: Govin
authors.forename: Liye
authors.initials: L
authors.lastname: Zhang
authors.forename: Greg
authors.initials: G
authors.lastname: Donahue
authors.forename: B Franklin
authors.initials: BF
authors.lastname: Pugh
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Berger
mesh_terms: D001483:Base Sequence; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D005718:Gametogenesis / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006657:Histones / Q000378:metabolism*; D008540:Meiosis / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004271:DNA, Fungal; C480035:HHO1 protein, S cerevisiae; D006657:Histones; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C089979:UME6 protein, S cerevisiae