Project description:MicroRNAs (miRNAs), a class of small non-coding RNAs, are key regulators of gene expression at post-transcriptional level and play essential roles in fundamental biological processes such as metabolism and development. The particular developmental characteristics of cestode parasites highlight the importance of studying miRNA gene regulation in these organisms. Here, we performed a comprehensive analysis of miRNAs in two developmental stages of the model cestode Mesocestoides corti. Using a high-throughput sequencing approach, we found transcriptional evidence of 42 miRNA loci in tetrathyridia larvae and strobilated worms. Tetrathyridium and strobilated worm-specific miRNAs were found, as well as differentialy expressed miRNAs between these developmental stages, suggesting miRNA regulation of stage-specific features. Moreover, it was shown that uridylation is a differential mechanism of post-transcriptional modification of M. corti miRNAs. The whole set of M. corti miRNAs represent 33 unique miRNA families, and confirm the remarkable loss of conserved miRNA families within platyhelminth parasites, reflecting their relatively low morphological complexity and high adaptation to parasitism. Overall, the presented results provide a valuable platform to studies aiming to identify and characterize novel miRNA-based molecular mechanisms of post-transcriptional gene regulation in cestodes, necessary for the elucidation of developmental aspects of the complex biology of these parasites.
2016-11-24 | GSE85058 | GEO
Project description:Transcriptomic profile of two developmental stages of the cestode parasite Mesocestoides corti.
Project description:Cre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation. We used microarrays to examine gene expression in apical versus basal organ of Corti from the cochleae of control and mutant mice in which Dicer1 was deleted and microRNAs were depleted specifically in sensory hair cells by Atoh1 promoter-driven Cre recombinase expression. Each biological replicate represents the combined apical or combined basal segments of organ of Corti from both cochleae of a single mouse. Two biological replicates for apical and basal organ of Corti from Dicer1 conditonal knockout and littermate controls were collected for RNA extraction and microarray analysis.
Project description:Cre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation. We used microarrays to examine gene expression in apical versus basal organ of Corti from the cochleae of control and mutant mice in which Dicer1 was deleted and microRNAs were depleted specifically in sensory hair cells by Atoh1 promoter-driven Cre recombinase expression.
Project description:To understand the basic biological properties of supporting cells of the mammalian inner ear, we examined the transcriptome of adult pillar and Deiters’ cells. Morphologically distinct pillar and Deiters’ cells were isolated from the organ of Corti from adult CBA/J mice. One thousand pillar and Deiters’ cells were separately collected for each biological replicate, using the suction pipette technique. RNA sequencing of three biological replicates, each with two technical repeats, was performed. The resulting sequenced reads were mapped. Comparisons between pillar cells and Deiters’ cells allow identification of enriched genes, as well as differentially expressed genes that result in cellular specialization. Our dataset provides an extensive resource for understanding the molecular mechanisms underlying morphology, function, and pathology of adult mouse pillar and Deiters’ cells.
Project description:Sensory hair cells cannot be regenerated through transdifferentiation of neighboring supporting cells in the organ of Corti in mature mammalian animals, but limited regeneration capacity exists in supporting cells at neonatal stage in mouse and this transdifferentiation potential is rapidly lost during the first week of postnatal maturtion. We hypothesized that epigenetic decommissioning of hair cell gene enhancers in supporting cells during postnatal maturation leads the permanent silencing of hair cell genes and the loss of transdifferentiation potential. To test this hypothesis, we FACS purified hair cells and supporting cells from cochleae at different developmental stages for transcritomic analysis (RNAseq), chromatin accessibility assay (ATACseq) and histone modification profiling (ChIPseq or CUT&RUN). We first defined hair cell genes and predicted their potential active enhancers. We found that hair cell gene promoters and enhancers were kept in a primed-but-silenced status (H3K4me1/3+, low H3K27ac but high H3K27me3) in supporting cells at neonatal stage. During postnatal maturation, hair cell gene enhancers are decommissioned through H3K4me1 removal, leading to the permanent silencing of hair cells genes. We also found that hair cell gene enhancer decommissioning process correlated with the base-to-apex wave of transdifferentiation potential loss. In addition, hair cell gene enhancer commissioning status is preserved in mature utricular supporting cells, which can regenerate hair cells through transdifferentiation even at adult stage. Those data together suggest that decommissioning of hair cell gene enhancers in supporting cells during postnatal maturation is the epigenetic mechanism underlying the loss of regeneration capacity in the organ of Corti.
Project description:To further understand the biological properties of hair cells of the mammalian cochlea, we examined the transcriptome of adult inner and outer hair cells. Morphologically distinct inner and outer hair cells were isolated from the organ of Corti from adult CBA/J mice. One thousand inner and outer hair cells were separately collected for each biological replicate, using the suction pipette technique. RNA sequencing of two biological replicates of IHCs and three biological replicates of OHCs, each with two technical repeats, was performed. The resulting sequenced reads were mapped. Comparisons between inner and outer hair cells allow identification of enriched genes, as well as differentially expressed genes that result in cellular specialization. Our dataset provides an extensive resource for understanding the molecular mechanisms underlying morphology, function, and pathology of adult mouse inner and outer hair cells.
Project description:We report on gene expression, chromatin accessibility, active histone marks distribution, and Tead DNA-binding in proliferating and postmitotic organ of Corti progenitor cells.
Project description:Genomic assembly of cestode Mesocestoides corti, as part of the 50 Helminth Genomes Initiative; sequencing of the parasitic worms that have the greatest impact on human, agricultural and veterinary disease and cause significant global health issues particularly in the developing world, or those used as model organisms.