Project description:This SuperSeries is composed of the following subset Series: GSE22453: Custom MHC array analysis of lymphoblastoid cell lines GSE22454: Affymetrix Human Exon 1.0 ST array analysis of lymphoblastoid cell lines Refer to individual Series
Project description:This experiment accompanies the main analysis using a custom MHC array to define the first high-resolution, strand-specific transcriptional map of the MHC, defining differences in gene expression for three common haplotypes associated with autoimmune disease. Unstimulated samples for each haplotype were hybridised to Affymetrix Human Exon 1.0 ST arrays as well the custom MHC array. Exon array data were used to assess the concordance of signal obtained from the two platforms and to investigate the extent of alternative splicing in the MHC, and how it compares to the rest of the genome. Lymphoblastoid cell lines carrying three common autoimmunity haplotypes (COX, PGF, QBL) were analysed in triplicate using the Affymetrix Human Exon 1.0 ST Array.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes