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:The vomeronasal organ (VNO) of mice contains two main types of vomeronasal sensory neurons (VSNs)- Apical and Basal. Apical VSNs express vomeronasal receptors (VRs) of the V1R family and project to the anterior accessory olfactory bulb (AOB) and VSNs in the basal portions of the epithelium express receptors of the V2R family and project to the posterior portion of the AOB. In the vomeronasal epithelium of mice we found active BMP signaling. By generating Smad4 conditional mutants we disrupted canonical TGF-b/BMP signaling in either maturing basal VSNs or in mature apical and basal VSNs.
Project description:This study demonstrates the baseline data of gradient gene expression in the cochlea. Especially for genes whose mutations cause autosomal dominant non syndromic hearing loss (Pou4f3, Slc17a8, Tmc1, and Crym) as well as genes important for cochlear function (Emilin-2 and Tectb), gradual expression changes help to explain the various pathological conditions. Four C57BL/6 mice aged 6 weeks cochlea samples including the lateral wall, stria vascularis, spiral ligament, spiral prominence, and the organ of corti were dissected and separated into the apical, middle and basal turns to compare gene expression profiles of each cochlea turn.
Project description:Latent regeneration potential has been found in neonatal supporting cells in the organ of Corti in mouse. Upon Notch inhibition by DAPT, postnatal day 1 (P1) supporting cells transdifferentiate into hair cells. To profile the transcriptomic and epigenetic changes in supporting cells during transdifferentiation, we FACS purified supporting cells from DAPT treated cochleae for RNAseq, ATACseq and H3K27ac CUT&RUN. We found that hair cell genes were up-regulated in supporting cells after DAPT treatment and that hair cell gene induction was accompanied by epigentic activation of hair cell gene cis-regulatory elements through chromatin accessibility increase and H3K27ac accumulation, suggesting the regulatory roles of epigenetic activation of hair cell gene elements for hair cell gene expression induction.
Project description:We purified seven different cell populations and performed RNA sequencing to profile transcriptional similarities and differences between them. The seven cell types were 1) Atoh1-GFP positive cochlear hair cells from the organ of Corti of postnatal day one mice, 2) Atoh1-GFP negative cells from the organ of Corti of postnatal day one mice, 3) Atoh1-GFP positive induced hair cells generated by overexpression of Six1, Atoh1, Pou4f3, and Gfi1, 4) dsRed transduced control mouse embryonic fibroblasts, 5) Atoh1-GFP positive Merkel cells from postnatal day 1 mice, 6) Atoh1-GFP positive Cerebellar granule precursor cells from postnatal day 1 mice, and 7) Atoh1-GFP positive Gut secretory cells from postnatal day one mice.
Project description:We purified seven different cell populations and performed RNA sequencing to profile transcriptional similarities and differences between them. The seven cell types were 1) Atoh1-GFP positive cochlear hair cells from the organ of Corti of postnatal day one mice, 2) Atoh1-GFP negative cells from the organ of Corti of postnatal day one mice, 3) Atoh1-GFP positive induced hair cells generated by overexpression of Six1, Atoh1, Pou4f3, and Gfi1, 4) dsRed transduced control mouse embryonic fibroblasts, 5) Atoh1-GFP positive Merkel cells from postnatal day 1 mice, 6) Atoh1-GFP positive Cerebellar granule precursor cells from postnatal day 1 mice, and 7) Atoh1-GFP positive Gut secretory cells from postnatal day one mice.
Project description:We purified seven different cell populations and performed RNA sequencing to profile transcriptional similarities and differences between them. The seven cell types were 1) Atoh1-GFP positive cochlear hair cells from the organ of Corti of postnatal day one mice, 2) Atoh1-GFP negative cells from the organ of Corti of postnatal day one mice, 3) Atoh1-GFP positive induced hair cells generated by overexpression of Six1, Atoh1, Pou4f3, and Gfi1, 4) dsRed transduced control mouse embryonic fibroblasts, 5) Atoh1-GFP positive Merkel cells from postnatal day 1 mice, 6) Atoh1-GFP positive Cerebellar granule precursor cells from postnatal day 1 mice, and 7) Atoh1-GFP positive Gut secretory cells from postnatal day one mice.
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.