Explore Workflows

A basic differential methylation analysis workflow using BismarkCov formatted bed files as input to the RnBeads tool. Analysis is conducted on region and sites levels according to the sample groups specified by user (limited to 2 conditions in this workflow implementation). See report html files for detailed descriptions of analyses and results interpretation. ### __Inputs__ *General Info:* - Experiment short name/Alias* - a unique name for the sample (e.g. what was used on tubes while processing it) - Condition 1 name - name defining condition/group 1 - Condition 2 name - name defining condition/group 2 - Bismark coverage files* for condition1 - minumum of 2 is required for analysis - Bismark coverage files* for condition2 - minumum of 2 is required for analysis - Sample genome - available options: hg19, hg38, mm9, mm10, rn5 - Genome type - indicate mismark index used for upstream samples (input for conditions 1 and 2) *Advanced:* - Number of threads for steps that support multithreading - default set to `4` *[BismarkCov formatted bed](https://www.bioinformatics.babraham.ac.uk/projects/bismark/Bismark_User_Guide.pdf): The genome-wide cytosine report (optional) is tab-delimited in the following format (1-based coords): <chromosome> <position> <strand> <count methylated> <count unmethylated> <C-context> <trinucleotide context> ### __Outputs__ Intermediate and final downloadable outputs include: - sig_dm_sites.bed ([bed for IGV](https://genome.ucsc.edu/FAQ/FAQformat.html#format1); sig diff meth sites) - sig_dm_sites_annotated.tsv (tsv for TABLE; for each site above, closest single gene annotation) - Site_id, unique indentifer per methylated site - Site_Chr, chromosome of methylated site - Site_position, 1-based position in chr of methylated site - Site_strand, strand of methylated site - Log2_Meth_Quotient, log2 of the quotient in methylation: log2((mean.g1+epsilon)/(mean.g2+epsilon)), where epsilon:=0.01. In case of paired analysis, it is the mean of the pairwise quotients. - FDR, adjusted p-values, all <0.10 assumed to be significant - Coverage_score, value between 0-1000 reflects strength of mean coverage difference between conditions and equals [1000-(1000/(meancov_g1-meancov_g2)^2](https://www.wolframalpha.com/input?i=solve+1000-%281000%2F%28x%5E2%29%29), if meancov_g1-meancov_g2==0, score=0, elif score<1==1, else score - meancov_g1, mean coverage of condition1 - meancov_g2, mean coverage of condition2 - refSeq_id, RefSeq gene id - Gene_id, gene symbol - Chr, gene chromosome - txStart, gene transcription start position - tsEnd, gene transcription end position - txStrand, gene strand - stdout and stderr log files - Packaged RnBeads reports directory (reports.tar.gz) contains: reports/ ├── configuration ├── data_import.html ├── data_import_data ├── data_import_images ├── data_import_pdfs ├── differential_methylation.html ├── differential_methylation_data ├── differential_methylation_images ├── differential_methylation_pdfs ├── preprocessing.html ├── preprocessing_data ├── preprocessing_images ├── preprocessing_pdfs ├── quality_control.html ├── quality_control_data ├── quality_control_images ├── quality_control_pdfs ├── tracks_and_tables.html ├── tracks_and_tables_data ├── tracks_and_tables_images └── tracks_and_tables_pdfs Reported methylation is in the form of regions (genes, promoters, cpg, tiling) and specific sites: - genes - Ensembl gene definitions are downloaded using the biomaRt package. - promoters - A promoter is defined as the region spanning 1,500 bases upstream and 500 bases downstream of the transcription start site of the corresponding gene - cpg - the CpG islands from the UCSC Genome Browser - tiling - a window size of 5 kilobases are defined over the whole genome - sites - all cytosines in the context of CpGs in the respective genome ### __Data Analysis Steps__ 1. generate sample sheet with associated conditions for testing in RnBeads 2. setup rnbeads analyses in R, and run differential methylation analysis 3. process output diffmeth files for regions and sites 4. find single closest gene annotations for all significantly diffmeth sites 5. package and save rnbeads report directory 6. clean up report dir for html outputs ### __References__ - https://rnbeads.org/materials/example_3/differential_methylation.html - Makambi, K. (2003) Weighted inverse chi-square method for correlated significance tests. Journal of Applied Statistics, 30(2), 225234 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4216143/ - Assenov Y, Müller F, Lutsik P, Walter J, Lengauer T, Bock C. Comprehensive analysis of DNA methylation data with RnBeads. Nat Methods. 2014 Nov;11(11):1138-1140. doi: 10.1038/nmeth.3115. Epub 2014 Sep 28. PMID: 25262207; PMCID: PMC4216143.

https://github.com/datirium/workflows.git

Path: workflows/diffmeth.cwl

Branch/Commit ID: 675a3ff982091faf304931e9261aacdbabf51702

https://github.com/common-workflow-language/cwl-v1.2.git

Path: tests/scatter-valuefrom-wf6.cwl

Branch/Commit ID: a5073143db4155e05df8d2e7eb59d9e62acd65a5

https://github.com/ncbi/pgap.git

Path: task_types/tt_cache_asnb_entries.cwl

Branch/Commit ID: a2d6cd4c53bf3501f6bd79edebb7ca30bba8456f

https://github.com/genome/analysis-workflows.git

Path: definitions/subworkflows/fastq_to_bqsr.cwl

Branch/Commit ID: a23f42ef49c10a588fd35a3afaad5de03e253533

Deprecated. AltAnalyze Build Reference Indices

https://github.com/datirium/workflows.git

Path: workflows/altanalyze-prepare-genome.cwl

Branch/Commit ID: 7030da528559c7106d156284e50ff0ecedab0c4e

Cross-Linking ImmunoPrecipitation ================================= `CLIP` (`cross-linking immunoprecipitation`) is a method used in molecular biology that combines UV cross-linking with immunoprecipitation in order to analyse protein interactions with RNA or to precisely locate RNA modifications (e.g. m6A). (Uhl|Houwaart|Corrado|Wright|Backofen|2017)(Ule|Jensen|Ruggiu|Mele|2003)(Sugimoto|König|Hussain|Zupan|2012)(Zhang|Darnell|2011) (Ke| Alemu| Mertens| Gantman|2015) CLIP-based techniques can be used to map RNA binding protein binding sites or RNA modification sites (Ke| Alemu| Mertens| Gantman|2015)(Ke| Pandya-Jones| Saito| Fak|2017) of interest on a genome-wide scale, thereby increasing the understanding of post-transcriptional regulatory networks. The identification of sites where RNA-binding proteins (RNABPs) interact with target RNAs opens the door to understanding the vast complexity of RNA regulation. UV cross-linking and immunoprecipitation (CLIP) is a transformative technology in which RNAs purified from _in vivo_ cross-linked RNA-protein complexes are sequenced to reveal footprints of RNABP:RNA contacts. CLIP combined with high-throughput sequencing (HITS-CLIP) is a generalizable strategy to produce transcriptome-wide maps of RNA binding with higher accuracy and resolution than standard RNA immunoprecipitation (RIP) profiling or purely computational approaches. The application of CLIP to Argonaute proteins has expanded the utility of this approach to mapping binding sites for microRNAs and other small regulatory RNAs. Finally, recent advances in data analysis take advantage of cross-link–induced mutation sites (CIMS) to refine RNA-binding maps to single-nucleotide resolution. Once IP conditions are established, HITS-CLIP takes ~8 d to prepare RNA for sequencing. Established pipelines for data analysis, including those for CIMS, take 3–4 d. Workflow -------- CLIP begins with the in-vivo cross-linking of RNA-protein complexes using ultraviolet light (UV). Upon UV exposure, covalent bonds are formed between proteins and nucleic acids that are in close proximity. (Darnell|2012) The cross-linked cells are then lysed, and the protein of interest is isolated via immunoprecipitation. In order to allow for sequence specific priming of reverse transcription, RNA adapters are ligated to the 3' ends, while radiolabeled phosphates are transferred to the 5' ends of the RNA fragments. The RNA-protein complexes are then separated from free RNA using gel electrophoresis and membrane transfer. Proteinase K digestion is then performed in order to remove protein from the RNA-protein complexes. This step leaves a peptide at the cross-link site, allowing for the identification of the cross-linked nucleotide. (König| McGlincy| Ule|2012) After ligating RNA linkers to the RNA 5' ends, cDNA is synthesized via RT-PCR. High-throughput sequencing is then used to generate reads containing distinct barcodes that identify the last cDNA nucleotide. Interaction sites can be identified by mapping the reads back to the transcriptome.

https://github.com/datirium/workflows.git

Path: workflows/clipseq-se.cwl

Branch/Commit ID: ebbf23764ede324cabc064bd50647c1f643726fa

https://github.com/common-workflow-language/cwltool.git

Path: cwltool/schemas/v1.0/v1.0/count-lines6-wf.cwl

Branch/Commit ID: 7ec307b01442936fad9b1149f4500496557505ff

https://github.com/genome/analysis-workflows.git

Path: definitions/pipelines/bisulfite.cwl

Branch/Commit ID: 4bc0a4577d626b65a4b44683e5a1ab2f7d7faf4c

https://github.com/common-workflow-language/cwltool.git

Path: cwltool/schemas/v1.0/v1.0/count-lines6-wf.cwl

Branch/Commit ID: e8b3565a008d95859fc44227987a54e6a53a8c29

https://github.com/genome/analysis-workflows.git

Path: definitions/pipelines/somatic_wgs.cwl

Branch/Commit ID: 42c66dd24ce5026d3f717214ddb18b7b4fae93cf