Project description:Reference experiment of wild type Saccharomyces cerevisiae cells of the BJ5457 background. Cells were grown in synthetic complete medium (SC) with the addition of the necessary aminoacids and factors (leucine, uracil, histidine, tryptophane) and harvested in exponential phase (OD=0.7-1). Cells were grown in the presence of BCS and BPS chelators. <br>
Project description:Wild-type and isogenic H3K37R yeast cultures were grown in medium containing 2% raffinose as carbone source. Cells were synchronized in G1 with alpha factor. To half culture (100ml), glucose (2% final concentration) and 1.3ml BrdU (50mg/ml stock) and 1.3ml BrdU (50mg/ml stock) was added. To the other half, galactose (2% final concentration) and 1.3ml BrdU (50mg/ml stock). Both flasks were incubated for further 30min at 30C, then cell were collected by centrifugation and resuspended into 100ml of 30C warmed YPA-2%Glucose or YPA-2%Galactose medium containing 25ml HU (2M stock) plus 1.2 ml BrdU (50mg/ml stock) and incubated for 1 hour and 10minutes. YPA-Glucose and YPA-Galactose cultures were immediately transferred to ice/water bath and replication was stopped by addition of NaN3 and cells were processed for DNA immunoprecipitation with anti BrdU antibody.
Project description:Yeast RNA polymerase (Pol) II consists of a ten-subunit core enzyme and the Rpb4/7 subcomplex, which is dispensable for catalytic activity and dissociates in vitro. To investigate whether Rpb4/7 is an integral part of DNA-associated Pol II in vivo, we used chromatin immuno-precipitation coupled to high-resolution tiling microarray analysis. We show that the genome-wide occupancy profiles for Rpb7 and the core subunit Rpb3 are essentially identical. Thus, the complete Pol II associates with DNA in vivo, consistent with functional roles of Rpb4/7 throughout the transcription cycle. Keywords: ChIP-chip Comparison of Rpb3 vs. Rpb4/7 genome-wide occupancy profiles. Data obtained from independent ChIP-chip experiments on two yeast strains: S288C Rpb3TAP vs. Rpb7-TAP strain and W303 Rpb3-TAP vs. wild type strain (IP with the monoclonal antibody for Rpb4/7). Biological replicates W303 strains: 1 x Rpb3-TAP, 1 x wt with Rpb4/7 antibody, independently grown and harvested. Biological replicates S288C strains: 3 x Rpb3-TAP, 2 x Rpb7-TAP, independently grown and harvested. One replicate per array.
Project description:Selected human sperms with ART technique demonstrate many changes in the genetic and epigenetic aspects. There are many evidances shown that DNA damange and histone retention ratio have significant improved after selection with different methods. These changes may relate with DNA epigenetic changes, however no evidance demonstate these relevance. In this study, MeDIP-ChIP method has been employed to detect DNA methylation loci in human sperm genome processed with density selection. Results demonstrated that DNA methylation changed in specific gene location. comparison the DNA methylation site between 3 pair human sperm DNA samples before or after density selection
Project description:Homologous recombination (HR) is crucial for genetic exchange, accurate repair of DNA double-strand breaks and pivotal for genome integrity. HR uses homologous sequences for repair, but how homology search, the exploration of the genome for homologous DNA sequences, is conducted in the nucleus remains poorly understood. Here, we use time-resolved chromatin immunoprecipitations of repair proteins to monitor homology search in vivo. We found that homology search proceeds by a probing mechanism, which commences around the break and samples preferentially on the broken chromosome. However, elements thought to instruct chromosome loops mediate homology search shortcuts, and centromeres, which cluster within the nucleus, may facilitate homology search on other chromosomes. Our study thus revealed crucial parameters for homology search in vivo and emphasizes the importance of linear distance, chromosome architecture and proximity for recombination efficiency. 2 new custom ChIP-chip platforms used; both Nimblegen; differ in oligo density: (platform 1: 2006-07-18_Scerevisiae_ChIP_Stefan Jentsch MPI Biochemistry S.cerevisiae 385K Tiling Array Version 1) ( platform 2: 100304_Scer2_MS_Chip_Stefan Jentsch MPI Biochemistry S.cerevisiae 135K Tiling Array Version 2) ChIP-chip profiling of DSB repair factors (Rad51, Rad52, RPA, gamma-H2A) upon single inducible DSBs in S.cerevisiae