Project description:We analyzed the genome-wide expression profiles of mutant strains of two yeast species in which eight different chromatin regulators and one transcription factor were deleted (one gene deleted in each strain). Comparison of the inter-species expression differences between the wild-types of these species and their mutants showed that deletion of regulators tends to increase the amount of inter-species expression differences, suggestng that the regilators are normally buffering hidden variability. In addition, we measured allele-specific expresion levels of the interspecific hybrid formed by mating each of the two corresponding mutants (deleted for the same regulator). Keywords: Comparative transcriptome analysis
Project description:We analyzed the genome-wide expression profiles of mutant strains of two yeast species in which eight different chromatin regulators and one transcription factor were deleted (one gene deleted in each strain). Comparison of the inter-species expression differences between the wild-types of these species and their mutants showed that deletion of regulators tends to increase the amount of inter-species expression differences, suggestng that the regilators are normally buffering hidden variability. In addition, we measured allele-specific expresion levels of the interspecific hybrid formed by mating each of the two corresponding mutants (deleted for the same regulator). Keywords: Comparative transcriptome analysis Nine gene deletions were examined. For each gene deletion, there are four datasets - S.cerevisiae and S. paradoxus or the hybrid each with two biological repeats. These four datasets are contained within a single slide of our custom two-species microarray, as it includes two subarrays (blocks) and hybridization was performed with two dyes.
Project description:It is commonly, although not universally, accepted that most intra- and inter-specific genome sequence variations are more or less neutral, whereas a large fraction of organism-level phenotypic variations are adaptive. Gene expression levels are molecular phenotypes that bridge the gap between genotypes and corresponding organism-level phenotypes. Yet, it is unknown whether natural variations in gene expression levels are mostly neutral or adaptive. Here we address this fundamental question by genome-wide profiling and comparison of gene expression levels in nine yeast strains belonging to three closely related Saccharomyces species and originating from five different ecological environments.
Project description:Changes in gene regulation level have long been thought to play an important role in evolution and speciation, especially in primates. Over the past decade, comparative genomic studies have revealed extensive inter-species differences in gene expression levels yet we know much less about the extent to which regulatory mechanisms differ between species. To begin addressing this gap, we performed a comparative epigenetic study in primate lymphoblastoid cell lines (LCLs), to query the contribution of RNA polymerase II (Pol II) and four histone modifications (H3K4me1, H3K4me3, H3K27ac, and H3K27me3) to inter-species variation in gene expression levels. We found that inter-species differences in mark enrichment near transcription start sites are significantly more often associated with inter-species differences in the corresponding gene expression level than expected by chance alone. Interestingly, we also found that first-order interactions among the histone marks and Pol II do not markedly contribute to the degree of association between the marks and inter-species variation in gene expression levels, suggesting that the marginal effects of the five marks dominate this contribution.
Project description:We sequenced polyA-selected transcriptomes from three species (mouse, rat and chicken), four organs (brain, kidney, liver and testis) and five developmental stages (two embryonic stages, newborn, young adult and aged adult individuals). We analyzed gene expression pattern variations across species, organs and developmental stages for protein-coding and long non-coding RNA genes.
Project description:We propose a new microarray method, called an inter-species array, that can measure gene expression levels of multiple species at once. As the array operates simply by changing the probes on an Agilent commercial customized array, and conventional facilities and protocols can be used, the method is cost-efficient. We generated an array for humans, rats and mice that covers 6683 genes. The number of genes is larger than that of previous arrays. We measured the expression of genes in astrocyte cells for humans and rats, and in cortex cells for rats and mice. Single array with multiple species samples.
Project description:Pathological consequences of circadian misalignment, such as shift work, show considerable individual differences, but the lack of mechanistic understanding hinders precision prevention to prevent and mitigate disease symptoms. Here, we employed an integrative approach involving physiological, transcriptional, and histological phenotypes to examine inter-individual differences in pathological progression during the pre-symptomatic stage, prior to the development of irreversible diseases under chronic circadian misalignment, using wild-type mice exposed to chronic jet-lag (CJL). We observed that CJL markedly increased the prevalence of hepatic steatosis with pronounced inter-individual differences. Stratification of individual mice based on CJL-induced hepatic transcriptomic signature, validated by histopathological analysis, pinpoints dysregulation of lipid metabolism. Moreover, the period and power of intrinsic behavioral rhythms was found to significantly correlate with CJL-induced gene signatures. Together, our results suggest circadian rhythm robustness of the animals contribute to inter-individual variations in pathogenesis of circadian misalignment-induced diseases, and arise the possibility that these physiological indicators may be available for predictive hallmarks of circadian rhythm disorders.