Promoter ChIP-chip analysis in mouse testis reveals Y chromosome occupancy by HSF2.
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ABSTRACT:
SUBMITTER: Akerfelt M
PROVIDER: S-EPMC2496887 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Mapping of in vivo targets for HSF2 by using mammalian tissue material in a global ChIP-chip promoter screen. Chromatin was isolated from three wild-type (WT) mouse testes, crosslinked and sonicated into fragments of 100-500 bp, and the quality of the DNA was controlled before the immunoprecipitation, showing no signs of degradation. The DNA amplified from the HSF2 immunoprecipitation samples was labeled and hybridized against the total input DNA samples, on a 1.5 kb promoter tiling array (NimbleGen Systems Inc.), covering ~26000 promoters of the mouse genome. After hybridization and scanning, HSF2 hybridization signals were Lowess normalized to produce log2 ratios (HSF2 ChIP/Input DNA) for all replicate arrays. The promoter values were calculated as average log2 ratios over all probes for each promoter. To identify the HSF2 target population, we used a non-arbitrary analysis method called RankProd described in Breitling et al. 2004. RankProd has been published as an R/Bioconductor package. Keywords: 1.5 kb mouse promoter ChIP-chip (MM5, NimbleGen Systems Inc.), mouse testis HSF2 ChIP sample vs. Input sample (reference), biological replicates: 3, one replicate per array.
2008-08-05 | E-GEOD-9289 | biostudies-arrayexpress
Project description:Mapping of in vivo targets for HSF2 by using mammalian tissue material in a global ChIP-chip promoter screen. Chromatin was isolated from three wild-type (WT) mouse testes, crosslinked and sonicated into fragments of 100-500 bp, and the quality of the DNA was controlled before the immunoprecipitation, showing no signs of degradation. The DNA amplified from the HSF2 immunoprecipitation samples was labeled and hybridized against the total input DNA samples, on a 1.5 kb promoter tiling array (NimbleGen Systems Inc.), covering ~26000 promoters of the mouse genome. After hybridization and scanning, HSF2 hybridization signals were Lowess normalized to produce log2 ratios (HSF2 ChIP/Input DNA) for all replicate arrays. The promoter values were calculated as average log2 ratios over all probes for each promoter. To identify the HSF2 target population, we used a non-arbitrary analysis method called RankProd described in Breitling et al. 2004. RankProd has been published as an R/Bioconductor package. Keywords: 1.5 kb mouse promoter ChIP-chip (MM5, NimbleGen Systems Inc.), mouse testis
2008-08-06 | GSE9289 | GEO
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Project description:The Hspa1b gene is one of the first genes expressed after fertilization, with expression observed in the male pronucleus as early as the one-cell stage of embryogenesis. This expression can occur in the absence of stress and is initiated during the minor zygotic genome activation. There is a significant reduction in the number of embryos developing to the blastocyte stage when HSPA1B levels are depleted, which supports the importance of this protein for embryonic viability. However, the mechanism responsible for allowing expression of Hspa1b during the minor zygotic genome activation (ZGA) is unknown. In this report, we investigated the role of HSF1 and HSF2 in bookmarking Hspa1b during late spermatogenesis. Western blot results show that both HSF1 and HSF2 are present in epididymal spermatozoa, and immunofluorescence analysis revealed that some of the HSF1 and HSF2 proteins in these cells overlap the 4',6'-diamidino-2-phenylindole-stained DNA region. Results from chromatin immunoprecipitation assays showed that HSF1, HSF2, and SP1 are bound to the Hspa1b promoter in epididymal spermatozoa. Furthermore, we observed an increase in HSF2 binding to the Hspa1b promoter in late spermatids versus early spermatids, suggesting a likely period during spermatogenesis when transcription factor binding could occur. These results support a model in which the binding of HSF1, HSF2, and SP1 to the promoter of Hspa1b would allow the rapid formation of a transcription-competent state during the minor ZGA, thereby allowing Hspa1b expression.
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