LongSAGE profiling of nine human embryonic stem cell lines

Analysis of a 2.6 million longSAGE sequence tag resource generated from nine human embryonic stem cell lines reveals an enrichment of RNA binding proteins and novel ES-specific transcripts

Application of massively parallel sequencing to microRNA profiling and discovery in human embryonic stem cells

MicroRNAs (miRNAs) are emerging as important, albeit poorly characterized, regulators of biological processes. Key to further elucidation of their roles is the generation of more complete lists of their numbers and expression changes in different cell states. Here, we report a new method for surveying the expression of small RNAs, including microRNAs, using Illumina sequencing technology. We also present a set of methods for annotating sequences deriving from known miRNAs, identifying variability in mature miRNA sequences, and identifying sequences belonging to previously unidentified miRNA genes. Application of this approach to RNA from human embryonic stem cells obtained before and after their differentiation into embryoid bodies revealed the sequences and expression levels of 334 known plus 104 novel miRNA genes. One hundred seventy-one known and 23 novel microRNA sequences exhibited significant expression differences between these two developmental states. Owing to the increased number of sequence reads, these libraries represent the deepest miRNA sampling to date, spanning nearly six orders of magnitude of expression. The predicted targets of those miRNAs enriched in either sample shared common features. Included among the high-ranked predicted gene targets are those implicated in differentiation, cell cycle control, programmed cell death, and transcriptional regulation

Large-scale production of SAGE libraries from microdissected tissues, flow-sorted cells, and cell lines

We describe the details of a serial analysis of gene expression (SAGE) library construction and analysis platform that has enabled the generation of >298 high-quality SAGE libraries and >30 million SAGE tags primarily from sub-microgram amounts of total RNA purified from samples acquired by microdissection. Several RNA isolation methods were used to handle the diversity of samples processed, and various measures were applied to minimize ditag PCR carryover contamination. Modifications in the SAGE protocol resulted in improved cloning and DNA sequencing efficiencies. Bioinformatic measures to automatically assess DNA sequencing results were implemented to analyze the integrity of ditag structure, linker or cross-species ditag contamination, and yield of high-quality tags per sequence read. Our analysis of singleton tag errors resulted in a method for correcting such errors to statistically determine tag accuracy. From the libraries generated, we produced an essentially complete mapping of reliable 21-base-pair tags to the mouse reference genome sequence for a meta-library of ∼5 million tags. Our analyses led us to reject the commonly held notion that duplicate ditags are artifacts. Rather than the usual practice of discarding such tags, we conclude that they should be retained to avoid introducing bias into the results and thereby maintain the quantitative nature of the data, which is a major theoretical advantage of SAGE as a tool for global transcriptional profiling

A set of BAC clones spanning the human genome

Using the human bacterial artificial chromosome (BAC) fingerprint-based physical map, genome sequence assembly and BAC end sequences, we have generated a fingerprint-validated set of 32 855 BAC clones spanning the human genome. The clone set provides coverage for at least 98% of the human fingerprint map, 99% of the current assembled sequence and has an effective resolving power of 79 kb. We have made the clone set publicly available, anticipating that it will generally facilitate FISH or array-CGH-based identification and characterization of chromosomal alterations relevant to disease

Integrated and Sequence-Ordered BAC- and YAC-Based Physical Maps for the Rat Genome

As part of the effort to sequence the genome of Rattus norvegicus, we constructed a physical map comprised of fingerprinted bacterial artificial chromosome (BAC) clones from the CHORI-230 BAC library. These BAC clones provide ∼13-fold redundant coverage of the genome and have been assembled into 376 fingerprint contigs. A yeast artificial chromosome (YAC) map was also constructed and aligned with the BAC map via fingerprinted BAC and P1 artificial chromosome clones (PACs) sharing interspersed repetitive sequence markers with the YAC-based physical map. We have annotated 95% of the fingerprint map clones in contigs with coordinates on the version 3.1 rat genome sequence assembly, using BAC-end sequences and in silico mapping methods. These coordinates have allowed anchoring 358 of the 376 fingerprint map contigs onto the sequence assembly. Of these, 324 contigs are anchored to rat genome sequences localized to chromosomes, and 34 contigs are anchored to unlocalized portions of the rat sequence assembly. The remaining 18 contigs, containing 54 clones, still require placement. The fingerprint map is a high-resolution integrative data resource that provides genome-ordered associations among BAC, YAC, and PAC clones and the assembled sequence of the rat genome

De novo assembly and analysis of RNA-seq data

We describe Trans-ABySS, a de novo short-read transcriptome assembly and analysis pipeline that addresses variation in local read densities by assembling read substrings with varying stringencies and then merging the resulting contigs before analysis. Analyzing 7.4 gigabases of 50-base-pair paired-end Illumina reads from an adult mouse liver poly(A) RNA library, we identified known, new and alternative structures in expressed transcripts, and achieved high sensitivity and specificity relative to reference-based assembly methods. © 2010 Nature America, Inc. All rights reserved

Differentially expressed isoforms (as predicted by LongSAGE tag positions) for the transcript (see text)

The tag sequence at position 9 results in the loss of the 3' UTR region targeted by evolutionarily conserved miRNAs. Putative miRNA target sites were predicted using miRanda [34] and are represented by hashed boxes.<p><b>Copyright information:</b></p><p>Taken from "LongSAGE profiling of nine human embryonic stem cell lines"</p><p>http://genomebiology.com/2007/8/6/R113</p><p>Genome Biology 2007;8(6):R113-R113.</p><p>Published online 14 Jun 2007</p><p>PMCID:PMC2394759.</p><p></p

Expression of selected transcripts during embryoid body differentiation

qPCR was used to monitor expression of selected transcripts in ESCs stimulated to differentiate into embryoid bodies. Three control markers, Oct4, Lin28 and Msx1, were included. Expression levels are reported as the mean of triplicate measurements and are normalized to GAPDH.<p><b>Copyright information:</b></p><p>Taken from "LongSAGE profiling of nine human embryonic stem cell lines"</p><p>http://genomebiology.com/2007/8/6/R113</p><p>Genome Biology 2007;8(6):R113-R113.</p><p>Published online 14 Jun 2007</p><p>PMCID:PMC2394759.</p><p></p