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Sample GSM1517271 Query DataSets for GSM1517271
Status Public on Apr 21, 2015
Title Pulsatile cAMP in suspension, replicate 2, hour 02
Sample type SRA
 
Source name Cells in Na+ K+ phosphate buffer shaking suspension
Organism Dictyostelium discoideum
Characteristics strain: AX4
growth: HL-5
treatment: Exogenous cAMP in shaking suspension
time point (hour): 2
replicate: 2
Growth protocol Dictyostelium discoideum cells were grown in nutrient media (HL-5) to mid-log phase prior to collection for development.
Extracted molecule polyA RNA
Extraction protocol TriZol (Life Sciences) -- Cells were scraped (filter) or pelleted (suspension) and disrupted in TriZol. Total RNA was extracted by phenol/chloroform as per manufacturer's instructions.
mRNA was enriched by 2x polyA bead selection (Ambion, Life Sciences). Multiplexed libraries were constructed as outlined in Miranda et al (2013), PMID #23494306.
 
Library strategy RNA-Seq
Library source transcriptomic
Library selection cDNA
Instrument model Illumina Genome Analyzer II
 
Description Sample 51
PCrep2_hr02
Data processing After demultiplexing, the data was mapped to the D. discoideum genome with bowtie version 0.12.7. Read qualities were used. Other parameters: seed length = 28, allowed mismatches = 2, allowed up to 1 alignment per read, with bowtie options -a, --strata, --best. Unmapped reads were trimmed from 3' by 2 nucleotides, which was repeated 5 times.
Raw expression values were computed as the number of reads that were uniquely mapped to gene exons.
Normalized expression were scaled with mappable exon lengths. This normalization is similar to the RPKM normalization (Reads Per Kilobase of exon per Megabase of library size), but instead of dividing by exon lengths we used the uniquely mappable parts of the exon. To obtain uniquely mappable parts, all possible subsequences of the reference genome (of the same length as reads in raw data) are mapped back to the reference genome, obtaining the number of uniquely mapped sequences to the exons (Exon_mappable). As a library size we used the total number of all uniquely mapped reads from the experiment, excluding the non-polyadenylated genes (N_unique). Normalized expressions were computed as follows: Exp = 10^9*raw/(N_unique * Exon_mappable).
Genome_build: D. discoideum Chromosomal DNA: 1,2,3,4,5,6,M, and floating contigs (created: 05-13-2009 13:53) from the DictyBase (chromosomes 1,2,3,4,5,6 and mitochondrial DNA are the same as on NCBI assembly "dicty_2.7"). Regions [3016085, 3768655] from chr2, [64985, 72996] from chrBF and [42801, 78150] from chrR were masked.
Supplementary_files_format_and_content: Processed data files are tab-separated files with two columns: the first containing gene names (DDB_G ids) and the second its expression. Files ending with "_raw.txt" contain raw expression values while files ending with "_nor.txt" contain normalized expression values.
 
Submission date Sep 30, 2014
Last update date May 15, 2019
Contact name Gad Shaulsky
E-mail(s) gadi@bcm.edu
Organization name Baylor College of Medicine
Department Molecular and Human Genetics
Street address One Baylor Plaza
City Houston
State/province TX
ZIP/Postal code 77030
Country USA
 
Platform ID GPL9379
Series (1)
GSE61914 Leaps and lulls in the developmental transcriptome of Dictyostelium discoideum
Relations
BioSample SAMN03085010
SRA SRX717798

Supplementary file Size Download File type/resource
GSM1517271_PCrep2_hr02_nor.txt.gz 96.6 Kb (ftp)(http) TXT
GSM1517271_PCrep2_hr02_raw.txt.gz 47.7 Kb (ftp)(http) TXT
SRA Run SelectorHelp
Raw data are available in SRA
Processed data provided as supplementary file

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