Project description:Transcriptional profiling of NHDF Cells comparing control untreated fibroblasts with fibroblasts coincubated with three different species of the Borrelia burgdorferi sensu lato group.
Project description:Transcriptional control of gene expression is a result of complex interactions between the cis-regulatory elements (CRE) at gene promoters. To understand the regulatory logic of a cell, we need to identify the CRE combinations that regulate gene expression. We developed a sensitive computational method to identify phylogenetically conserved CRE combinations for any species of interest. In contrast to previous methods, we do not need to align genomes to identify these combinations. We applied the method in 7 sensu stricto and sensu lato Saccharomyces species. 80% of the predictions displayed some evidence of combinatorial transcriptional behavior in several existing datasets including 1) ChIP-chip data for co-localization of transcription factors, 2) gene expression data for co-expression of predicted regulatory targets, and 3) gene ontology databases for common pathway membership of predicted regulatory targets. To establish definitive evidence that these CRE interactions influence TF occupancy, we performed ChIPseq experiments on transcription factors in a wild-type strain and strains in which a predicted cofactor was deleted. Our experiments showed that TF occupancy at the promoters of the CRE combination target genes depends on the predicted cofactor while occupancy of other promoters is independent of the predicted cofactor. ChIP-seq of 6 myc-tagged Transcription factors in wild-type and predicted co-factor knockout yeast strains in triplicate
Project description:Transcriptional control of gene expression is a result of complex interactions between the cis-regulatory elements (CRE) at gene promoters. To understand the regulatory logic of a cell, we need to identify the CRE combinations that regulate gene expression. We developed a sensitive computational method to identify phylogenetically conserved CRE combinations for any species of interest. In contrast to previous methods, we do not need to align genomes to identify these combinations. We applied the method in 7 sensu stricto and sensu lato Saccharomyces species. 80% of the predictions displayed some evidence of combinatorial transcriptional behavior in several existing datasets including 1) ChIP-chip data for co-localization of transcription factors, 2) gene expression data for co-expression of predicted regulatory targets, and 3) gene ontology databases for common pathway membership of predicted regulatory targets. To establish definitive evidence that these CRE interactions influence TF occupancy, we performed ChIPseq experiments on transcription factors in a wild-type strain and strains in which a predicted cofactor was deleted. Our experiments showed that TF occupancy at the promoters of the CRE combination target genes depends on the predicted cofactor while occupancy of other promoters is independent of the predicted cofactor.
Project description:Mycobacterium abscessus [M. abscessus (sensu lato) or M. abscessus group] comprises three closely related taxa with taxonomic status under revision: M. abscessus sensu stricto, M. bolletii and M. massiliense. We describe here a simple, robust and cost effective PCR-based method for distinguishing among M. abscessus, M. massiliense and bolletii. Based on the M. abscessus ATCC 19977T genome, discriminatory regions were identified between M. abscessus and M. massiliense from array-based comparative genomic hybridization. A typing scheme using PCR primers designed for four of these locations was applied to 46 well-characterized clinical isolates comprising 29 M. abscessus, 15 M. massiliense and 2 M. bolletii previously identified by multi-target sequencing. Interestingly, 2 isolates unequivocally identified as M. massiliense were shown to have a full length erm(41) instead of the expected gene deletion and showed inducible clarithromycin resistance after 14 days. We propose using this PCR-based typing scheme combined with erm(41) PCR for a straightforward identification of M. abscessus, M. massiliense and M. bolletii and assessment of inducible clarithromycin resistance. This method can be easily implemented into a routine workflow providing subspecies level identification within 24 hours of isolation of M. abscessus group.