ABSTRACT: We have shown that Chrnb4-cre; Dicerflox/flox retinas (Dicer CKO) display a cone dystrophy by postnatal day P21, independent of rod degeneration. To elucidate which gene pathways were affected by Dicer loss, RNA sequencing was performed in whole neural retinas of P21 control and Dicer CKO mice. This experiment aims to identify which genes were differentially expressed between Dicer conditional knockout and control mice.
Project description:We have shown that Chrnb4-cre; Dicerflox/flox retinas (Dicer CKO) display a cone dystrophy by postnatal day P21, independent of rod degeneration. To elucidate which miRNAs were involved in such phenotype, miRNA sequencing was performed in whole retinas of P21 and 3.5 month old control and Dicer CKO mice. This experiment aims to identify which miRNAs were differentially expressed in Dicer conditional knockout mice when compared to control mice.
Project description:Epithelial-stromal interactions in the uterus are required for normal uterine functions such as pregnancy, and multiple signaling pathways are essential for this process. Although Dicer and microRNAs (miRNA) have been implicated in several reproductive processes, the specific role of Dicer and miRNA in uterine development is not known. To address the roles of miRNA in the regulation of these key uterine pathways, we generated a conditional knockout (cKO) of Dicer in the postnatal uterine epithelium and stroma using progesterone receptor (PR)-Cre. These Dicer cKO are sterile with small uteri, which demonstrate significant defects including absence of glandular epithelium and enhanced stromal apoptosis, beginning at postnatal day 15 with expression of Cre and deletion of Dicer. Although these mice had normal serum steroid hormone levels, critical uterine signaling pathways, including progesterone-responsive genes, Indian hedgehog signaling, and the Wnt/Beta-catenin canonical pathway, were dysregulated at the mRNA level. Gene expression profiling data from pools of Dicer cKO and control uteri groups, at 15 days. two group comparison
Project description:Epithelial-stromal interactions in the uterus are required for normal uterine functions such as pregnancy, and multiple signaling pathways are essential for this process. Although Dicer and microRNAs (miRNA) have been implicated in several reproductive processes, the specific role of Dicer and miRNA in uterine development is not known. To address the roles of miRNA in the regulation of these key uterine pathways, we generated a conditional knockout (cKO) of Dicer in the postnatal uterine epithelium and stroma using progesterone receptor (PR)-Cre. These Dicer cKO are sterile with small uteri, which demonstrate significant defects including absence of glandular epithelium and enhanced stromal apoptosis, beginning at postnatal day 15 with expression of Cre and deletion of Dicer. Although these mice had normal serum steroid hormone levels, critical uterine signaling pathways, including progesterone-responsive genes, Indian hedgehog signaling, and the Wnt/Beta-catenin canonical pathway, were dysregulated at the mRNA level.
Project description:DICER has a well-characterized role in the processing of microRNAs (miRNAs) and small interfering RNAs (siRNA) that are important for post-transcriptional gene regulation. Emerging evidence suggests that DICER also has several non-canonical functions beyond miRNA/siRNA biogenesis, for example in transcriptional gene silencing at the chromatin level, as well as in RNA degradation and maintenance of genomic integrity. We have shown that the function of DICER in germ cells is essential for normal spermatogenesis; male mice lacking DICER in postnatal male germ cells are infertile due to severe defects in haploid differentiation. To better understand the function of DICER in male germ cells, we immunoprecipitated DICER from juvenile mouse testes and performed mass spectrometric analysis to identify DICER-interacting proteins.
Project description:Dicer is an essential ribonuclease involved in the biogenesis of miRNA. Previous studies have reported that Dicer is dysregulated in multiple types of cancers. To investigate the downstream phosphoproteome of Dicer, we carried out phosphotyrosine profiling of the liver of Dicer knockout of mice. We employed antibody-based enrichment of phosphotyrosine containing peptides coupled with spike-in SILAC-based quantitation. Over 400 phosphoisites were identified in each condition while 290 phosphosites were quantitated in common. Amongst these, several key signaling molecules like receptor tyrosine kinase MET, MET, PDGFR, EPHA2, EPHB4 and IGF1R/INSR were hyperphosphorylated. Also, non-receptor tyrosine kinases of Src family and their downstream effector signaling partners including IRS2 and STAT3were found to be hyperphosphorylated. Our study indicates that there is significant alteration in the signaling pathways upon ablation of Dicer.
Project description:Background: Adult zebrafish spontaneously regenerate their retinas after damage. Although a number of genes and signaling pathways involved in regeneration have been identified, the extent of mechanisms regulating regeneration is unclear. Small non-coding RNAs, microRNAs (miRNAs), that regulate regeneration of various tissues in lower vertebrates were examined for their potential roles in regulating zebrafish retinal regeneration. Results: To investigate the requirement of miRNAs during zebrafish retinal regeneration, we knocked down the expression of the miRNA-processing enzyme Dicer in retinas prior to light-induced damage. Dicer loss significantly reduced proliferation of Müller glia-derived neuronal progenitor cells during regeneration. To identify individual miRNAs with roles in retina regeneration, we collected retinas at different stages of light damage and performed small RNA high-throughput sequencing. We identified subsets of miRNAs that were differentially expressed during active regeneration but returned to basal levels once regeneration was completed. To validate the roles of differentially expressed miRNAs, we knocked down 6 different miRNAs that were upregulated in expression during regeneration and demonstrated that they have distinct effects on neuronal progenitor cell proliferation and migration during retina regeneration. Conclusions: miRNAs are necessary for retinal regeneration. miRNA expression is dynamic during regeneration. miRNAs function during initiation and progression of retinal regeneration.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare small non-coding RNA profiling (snRNA-seq) in WT oocyte, sperm and 2PN stage embryos to those sperm and 2PN stage embryos derived from WT, Dicer cKO and Drosha cKO. We further study the roles of sperm-borne small RNA on fertilization and pre-implantation embryonic development. Methods: Small RNA profiles of adult wild-type (WT) oocytes, adult WT sperm, 2PN stage embryos, adult Dicer cKO/Drosha cKO sperm, 2PN stage embryos were generated by deep sequencing in duplicate, using Ion Torrent Proton. The sequence reads that passed quality filters were analyzed at the small RNA level with two methods: Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. Results: Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to the mouse genome (build mm9) and identified 16,014 small RNA (miRNA and endo-siRNA) in the oocyte, sperm and 2PN stage of WT and Dicer cKO/Drosha cKO mice with BWA workflow and 34,115 transcripts with TopHat workflow. Approximately 47% of the miRNAs showed differential expression between the WT and Dicer cKO sperm, ~52% of miRNAs were shown dysregulated in Drosha cKO sperm compared to those in WT sperm with a fold change ≥2.0 and p value <0.05. Data analysis with BWA and TopHat workflows revealed a significant overlap yet provided complementary insights in transcriptome profiling. Conclusions: Our study represents the first detailed analysis of small non-coding RNAs (miRNAs) in sperm and demonstrated that sperm-borne small RNAs are important for fertilization and early embrynic develoment, with biologic duplicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comparative investigations of small RNAs profiles in mouse sperm, oocytes and 2PN stage of embryos. Our results show that NGS offers a comprehensive and more accurate quantitative and qualitative evaluation of small RNA contents within sperm or oocytes/embryos. We conclude that RNA-seq based small RNAs characterization in gametes would expedite genetic network analyses and permit the dissection of complex biologic functions during fertilization and embryonic development.