Project description:Used a DNA tag sequencing and mapping strategy called gene identification signature (GIS) analysis, in which 5' and 3' signatures of full-length cDNAs are accurately extracted into paired-end ditags (PETs) that are concatenated for efficient sequencing and mapped to genome sequences to demarcate the transcription boundaries of every gene. GIS analysis is potentially 30-fold more efficient than standard cDNA sequencing approaches for transcriptome characterization. Keywords: Paired End DiTags
Project description:Targeted paired-end sequencing of cDNA from unfragmented nascent RNA from exponentially growing S. cerevisiae cells was employed to obtain Pol II transcription elongation and splicing information from single transcripts. Nascent RNA was prepared from the yeast chromatin fraction (Carrillo Oesterreich, Preibisch, Neugebauer, Mol Cell 2010) or enriched from total RNA with polyadenylated RNA depletion. The nascent 3â end was labeled with a 3â DNA adaptor through ligation. A PCR with a forward primer in the first exon of select intron-containing genes amplifies nascent transcripts of specific genes and ensures sequencing adaptor attachment for paired-end sequencing. With this approach co-transcriptional splicing progression with distance from the intron end could be analyzed for 87 genes. Note that the unmapped and mapped data also include genes that did not pass the read coverage requirements in SMIT analysis. Nascent RNA profiles for mainly intron-containing genes were generated with paired-end sequencing with Illumina HiSeq technology.
Project description:Used a DNA tag sequencing and mapping strategy called gene identification signature (GIS) analysis, in which 5' and 3' signatures of full-length cDNAs are accurately extracted into paired-end ditags (PETs) that are concatenated for efficient sequencing and mapped to genome sequences to demarcate the transcription boundaries of every gene. GIS analysis is potentially 30-fold more efficient than standard cDNA sequencing approaches for transcriptome characterization. Keywords: Paired End DiTags 5 zebrafish tissues examined.
Project description:Deep sequencing of transcriptomes allows quantitative and qualitative analysis of many RNA species in a sample, with parallel comparison of expression levels, splicing variants, natural antisense transcripts, RNA editing and transcriptional start and stop sites the ideal goal. By computational modeling, we show how libraries of multiple insert sizes combined with strand-specific, paired-end (SS-PE) sequencing can increase the information gained on alternative splicing, especially in higher eukaryotes. Despite the benefits of gaining SS-PE data with paired ends of varying distance, the standard Illumina protocol allows only non-strand-specific, paired-end sequencing with a single insert size. Here, we modify the Illumina RNA ligation protocol to allow SS-PE sequencing by using a custom pre-adenylated 3’ adaptor. We generate parallel libraries with differing insert sizes to aid deconvolution of alternative splicing events and to characterize the extent and distribution of natural antisense transcription in C. elegans. Despite stringent requirements for detection of alternative splicing, our data increases the number of intron retention and exon skipping events annotated in the Wormbase genome annotations by 127 % and 121 %, respectively. We show that parallel libraries with a range of insert sizes increase transcriptomic information gained by sequencing and that by current established benchmarks our protocol gives competitive results with respect to library quality.
Project description:To identificate long noncoding RNAs in maize, we profiled transcriptome of shoots and roots using non-directional paired-end RNA-seq based on poly(A) selection.
