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Sample GSM1341974 Query DataSets for GSM1341974
Status Public on Jul 08, 2016
Title RAD51_flower_phs1_ChIPSeq
Sample type SRA
 
Source name Flower, phs1 mutant, RAD51 ChIP
Organism Zea mays
Characteristics inbred line: B73
genotype/variation: phs1 mutant
tissue: flower
chip antibody: ZmRAD51 (custom made)
Extracted molecule genomic DNA
Extraction protocol Flowers at the zygotene stage of meiotic prophase I were collected from at least twenty maize tassels, fixed in 1% formaldehyde for 10 min, and then quenched in 0.125mM glycine for 5 min.
1.5g of fixed flowers were ground into fine power and homogenized in Chromatin Extraction Buffer A (10 mM Tris-HCl pH 8.0, 0.4 mM sucrose, 10 mM MgCl2, 1 mM PMSF, 5 mM β-mercaptoethanol, 1 tablet of cOmplete Protease Inhibitor Cocktail (Roche, Penzberg, Germany)) for 20 min at 4°C with gentle shaking. The suspension was filtered into a new 50 ml conical tube through 2 layers of Miracloth (EMD Millipore, Billerica, MA, USA), placed in a plastic funnel and centrifuged at 4,000 rpm for 20 min at 4°C. The pellet was resuspended in 1 ml of extraction buffer B (10 mM Tris-HCl pH 8.0, 0.25 M sucrose, 10 mM MgCl2, 1% Triton X-100, 1 mM PMSF, 5 mM β-mercaptoethanol, 1 μg/ml of cOmplete Protease Inhibitor Cocktail) and centrifuged at 14,000 rpm for 10 min. The pellet was resuspended in 500 μl of Extraction Buffer C (10 mM Tris-HCl pH 8.0, 1.7 M sucrose, 2 mM MgCl2, 0.15% Triton X-100, 1 mM PMSF, 5 mM β-mercaptoethanol, 1 μg/ml cOmplete Protease Inhibitor Cocktail), placed on top of 500 μl of Extraction Buffer C cushion and centrifuged at 14,000 rpm for 1 h at 4°C. The nuclei pellet was resuspended in 500 μl Nuclei Lysis Buffer (50 mM Tris–HCl pH 8.0, 10 mM EDTA, 1% SDS, 1 mM PMSF, 1 μg/ml cOmplete Protease Inhibitor Cocktail) to release chromatin.
The resulting chromatin was sonicated into fragments of average length of 500-1000 bp using eight sonicator pulses, five seconds each, and centrifuged at 14,000 rpm for 5 min at 4°C. The supernatant was diluted 10 fold with Dilution Buffer (16.7 mM Tris–HCl pH 8.0, 1.2 mM EDTA, 167 mM NaCl, 1.1% Triton X-100, 1 mM PMSF, 1 μg/ml cOmplete Protease Inhibitor Cocktail) and pre-cleared with Dynabeads Protein A (Invitrogen, Carlsbad, CA, USA). 10 μl of the pre-cleared chromatin was saved as chromatin input control sample. The remaining chromatin was incubated with antibodies overnight at 4°C, and then captured by Dynabeads Protein A. After incubation, beads were washed 5 times in the following buffers: (1) Low Salt Wash Buffer (20 mM Tris-HCl pH 8.0, 2 mM EDTA, 150 mM NaCl, 0.1% SDS, 1% Triton X-100), (2) High Salt Wash Buffer (20 mM Tris-HCl pH 8.0, 2 mM EDTA, 500 mM NaCl, 0.1% SDS, 1% Triton X-100), (3) LiCl Buffer (10 mM Tris-HCl pH 8.0, 1 mM EDTA, 250 mM LiCl, 1% NP-40, 1% sodium deoxycholate), and (4) TE Buffer, twice (10 mM Tris-HCl pH 8.0, 1 mM EDTA). Chromatin was eluted from beads with 200 μl Elution Buffer (50 mM Tris-HCl pH 8.0, 10 mM EDTA, 200 mM NaCl, 1% SDS), treated with RNase for 2h at 37°C, deproteinized with Proteinase K for 2h at 45°C, and decrosslinked at 65°C for 8 h. DNA was purified using MinElute PCR Purification Columns (Qiagen, Hilden, Germany). DNA concentration was quantified using Quant-IT dsDNA HS Assay Kit (Invitrogen).
 
Library strategy ChIP-Seq
Library source genomic
Library selection ChIP
Instrument model Illumina HiSeq 2000
 
Data processing Basecalls performed using CASAVA version 1.8.
ChIP-seq reads were aligned to the B73 reference genome sequence (release AGPv2) using the Burrows-Wheeler Aligner (BWA).
Data were filtered based on unique mapping.
Peaks were called with the following parameters: bandwidth = 800 bp, shift size = 400 bp.
Genome_build: B73 (release AGPv2)
Supplementary_files_format_and_content: Bed file was generated to represent peaks positions.
 
Submission date Mar 07, 2014
Last update date May 15, 2019
Contact name Wojciech Pawlowski
E-mail(s) mw729@cornell.edu
Organization name Cornell University
Department Plant Breeding and Genetics
Street address Bradfield Hall, Room 403
City Ithaca
State/province NY
ZIP/Postal code 14853
Country USA
 
Platform ID GPL15463
Series (2)
GSE55701 Genomic features shaping the landscape of meiotic double-strand break hotspots in maize [ChIP-Seq]
GSE84369 Genomic features shaping the landscape of meiotic double-strand break hotspots in maize
Relations
BioSample SAMN02677624
SRA SRX483000

Supplementary data files not provided
SRA Run SelectorHelp
Raw data are available in SRA
Processed data are available on Series record

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