Project description:RPL3L is a ribosomal protein expressed exclusively in adult straited muscle tissues, and a paralogue of the ubiquitously expressed RPL3. Here, we are looking into the effects of Rpl3l knockout on translation in adult mice hearts.
Project description:Charcot-Marie-Tooth (CMT) disease can be caused by mutations in Aminoacyl-tRNA-Synthetases, including G240R mutation in Glycyl-tRNA-Synthetase (GARS). Ribo-seq generates snapshots of translating ribosomes on mRNA and therefore allows analysis of ribosome pausing mRNA. Here we performed Ribo-seq on lysates of HEK293T cells overexpressing GARS, WT or G240R, to dissect mechanism of CMT linked with translation. We found that GARS G240R causes pausing of ribosomes with glycine codons in A-site. The effect is specific for 21 nt ribosome-protected fragments, produced by ribosomes with empty A-sites, suggestive of the deficit of charged Glycyl-tRNA in GARS G240R-CMT.
Project description:Purpose: The goal of this study is to identify the differential cardiac chromatin accessibility between WT and Smyd1 null (Smyd1-KO) hearts at E9.5 using ATAC-seq. Methods: Four hearts at E9.5 were pooled per genotype per replicate, and were then dissociated into single cells. 40,000 viable cells were taken for were lysed to isolate nuclei, which were treated with Tn5 transposase (Nextera DNA Sample Prep Kit, Illumina) to isolate DNA. Fragmented DNA was then amplified using bar-coded PCR primers and libraries were seuqenced. Results: 25851 differential peaks (2-fold change) were identified between E9.5 WT and Smyd1-KO hearts.
Project description:Purpose: The goal of this study is to identify the differential cardiac chromatin accessibility between WT and cardiomyocyte conditional knockout (Chd4-CMko) hearts at E10.5 using ATAC-seq. Methods: Three hearts at E10.5 were pooled per genotype per replicate, and were then dissociated into single cells. 40,000 viable cells were taken for were lysed to isolate nuclei, which were treated with Tn5 transposase (Nextera DNA Sample Prep Kit, Illumina) to isolate DNA. Fragmented DNA was then amplified using bar-coded PCR primers and libraries were seuqenced. Results: 15736 differential peaks (2-fold change) were identified between E10.5 WT and Chd4-CMko hearts.
Project description:Purpose: The goal of this study is to identify the differential cardiac transcriptome profiling between WT and Smyd1 null (Smyd1-KO) hearts at E9.5 using RNA-seq. Methods: mRNA profiles of E9.5 WT and Smyd1-KO mouse hearts were generated by deep sequencing, n=3 for each genotype, using Illumina HiSeq2500. The sequence reads were aligned to the mm10 reference genome using STAR via the bcbio-nextgen RNA-sequencing pipeline. Differential gene expression was determined by DEseq2. Results: 1756 genes were differentially expressed between WT and Smyd1-KO hearts [adjusted P value <0.05, |log2(Fold Change)| > 0.5], with 1130 upregulated and 626 downregulated in E9.5 Smyd1-KO hearts.
Project description:mRNAs are generally assumed to be loaded instantly with ribosomes upon entry into the cytoplasm. To measure ribosome density on nascent mRNA, we developed nascent Ribo-Seq (nRibo-Seq) by combining Ribo-Seq with progressive 4-thiouridine labelling. In mouse macrophages, we experimentally determined, for the first time, the lag between the appearance of nascent RNA and its association with ribosomes, which was calculated to be 20 - 22 min for bulk mRNA, and approximated the time it takes for mRNAs to be fully loaded with ribosomes to be 41 - 44 min. Notably, ribosomal loading time is adapted to gene function as rapid loading was observed with highly regulated genes. The lag and ribosomal loading time correlate positively with ORF size and mRNA half-life, and negatively with tRNA adaptation index. Similar results were obtained in mouse embryonic stem cells, where the lag in ribosome loading was even more pronounced with 35 - 38 min. We validated our measurements after stimulation of macrophages with lipopolysaccharide, where the lag between cytoplasmic and translated mRNA leads to uncoupling between input and ribosome-protected fragments. Uncoupling is stronger for mRNAs with long ORFs or half-lives, a finding we also confirmed at the level of protein production by nascent chain proteomics. As a consequence of the lag in ribosome loading, ribosome density measurements are distorted when performed under conditions where mRNA levels are far from steady state expression, and transcriptional changes affect ribosome density in a passive way. This study uncovers an unexpected and considerable lag in ribosome loading, and provides guidelines for the interpretation of Ribo-Seq data taking passive effects on ribosome density into account.
Project description:CCBE1 is a secreted extracellular matrix protein expressed by epicardial cells but its role during epicardial development was still unknown.Using a Ccbe1 knockout (KO) mouse model, we observed that loss of CCBE1 leads to congenital heart defects including thinner and hyper-trabeculated ventricular myocardium. In addition, Ccbe1 mutant hearts displayed reduced proliferation of cardiomyocyte and epicardial cells. RNA-seq data of CCBE1 KO and WT murine hearts indicated deregulation of genes associated with development and morphogenesis including the epithelial-to-mesenchymal transition.
Project description:Purpose: The goal of this study is to compare the cardiac transcriptome profiling (RNA-seq) of WT and CHD4-M195I hearts at E18.5 to conclude genes affected by this CHD4 mutation. Methods: mRNA profiles of E18.5 WT and CHD4-M195I mouse hearts were generated by deep sequencing, n=4 for each genotype, using Illumina HiSeq2500. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. Results: RNA-sequencing (RNA-seq) analyses on E18.5 WT and CHD4-M195I hearts and identified 323 genes that were differentially expressed [adjusted P value <0.05, |log2(Fold Change)| > 0.5], 113 upregulated and 210 downregulated in CHD4-M195I hearts.