Project description:Genome-wide DNA methylation profiling of blood duplicate samples (n=128) From Sister Study were used to evaluate how concordance between duplicates were improved at sample level by various methylation preprocessing pipelines
Project description:Polyploidy or whole genome duplication (WGD) provides raw genetic materials for sequence and expression evolution of duplicate genes. However, the mode and tempo of expression divergence between WGD duplicate genes in closely relates species and recurrent allopolyploids are poorly understood. Arabidopsis is a suitable system for testing the hypothesis that duplicate genes increase expression diversity and regulatory networks. In Arabidopsis, WGD occurred more than once prior to the split between Arabidopsis thaliana and Arabidopsis arenosa, and both natural and human-made allotetraploids are available. Comparative genomic hybridization analysis indicated that single-copy and duplicate genes after WGD were well preserved in A. thaliana and A. arenosa. Analysis of gene expression microarrays showed that duplicate genes generally had higher levels of expression divergence between two closely related species than single-copy genes. The proportion of the progenitors' duplicate genes that were nonadditively expressed in the resynthesized and natural allotetraploids was significantly higher than that of single-copy genes. Duplicate genes related to environmental stresses tended to be differentially expressed, and multi-copy duplicate genes were likely to diverge expression between progenitors and in the allotetraploids. Compared to single-copy genes, duplicate genes tend to contain TATA boxes and less DNA methylation in the promoter regions, facilitating transcriptional regulation by binding transcription factors and/or cis-and trans- acting proteins. The data suggest an important role of WGD duplicate genes in modulating diverse and novel gene expression changes in response to external environmental cues as well as internal genetic turmoil such as recurrent polyploidy events.
Project description:microRNAs are small, non-coding, single-stranded RNAs between 18-22 nucleotides long that regulate gene expression. Expression of microRNAs is altered in tumor compared to normal tissue; there is some evidence that these changes may be reflected in the serum of cancer cases compared to healthy individuals. This has yet to be examined in a prospective study where samples are collected before diagnosis. We used Affymetrix arrays to examine serum miRNA expression profiles in 410 participants in the Sister Study, a prospective cohort study of 50,884 women. All women in the cohort had never been diagnosed with breast cancer at the time of enrollment.
Project description:Genome wide DNA methylation profiles of whole blood from HIV positive men. The Illumina Infinium 450k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 480,000 CpGs. Dataset included 24 subjects from the USA. This data set was used as validation set for studying the effect of HIV viral load on host DNA methylation levels.
Project description:Genome wide DNA methylation profiles of whole blood from HIV positive men. The Illumina Infinium 450k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 480,000 CpGs. Dataset included 120 subjects from the USA but because of missing clinical characteristics only 109 subjects were used in the scientific publication. The study analyzed the effect of HIV viral load on host DNA methylation levels.