Foldback Exit Peeloff

Gallery / Realistic Pipelines

An auto-folded serpentine (`%%metro fold_threshold: 15`) where a return-row section exit splits a bundle to two downstream sections: one line continues level along the row, the other turns down to a lower loop. Regression fixture for the peel-off lane crossover at the exit -- the reversal must follow the continuing line through the peel-off junction so it stays level.

Mermaid source

examples/topologies/foldback_exit_peeloff.mmd

%%metro title: Fold-back exit peel-off
%%metro style: dark
%%metro fold_threshold: 15
%%metro file: fastq_in | FASTQ
%%metro file: report_out | HTML
%%metro line: dna | DNA (Tumor + Normal) | #4a90d9
%%metro line: rna | RNA (Tumor) | #e63946
%%metro line: realignment | Realignment (RNA) | #f5c542
%%metro line_order: definition
%%metro legend: bl

graph LR
    subgraph preprocessing [Pre-processing & Alignment]
        fastq_in[ ]
        fastqc[FastQC]
        fastp[fastp]
        bwa_mem[BWA-mem/BWA-mem2]
        star[STAR]
        samtools_merge[SAMtools Merge]

        fastq_in -->|dna,rna| fastqc
        fastqc -->|dna,rna| fastp
        fastp -->|dna| bwa_mem
        fastp -->|rna| star
        bwa_mem -->|dna| samtools_merge
        star -->|rna| samtools_merge
    end

    subgraph gatk_preproc [GATK Preprocessing]
        markduplicates[MarkDuplicates]
        splitncigar[SplitNCigarReads]
        baserecalibrator[BaseRecalibrator]
        applybqsr[ApplyBQSR]
        samtools_stats[SAMtools Stats]
        mosdepth[Mosdepth]

        markduplicates -->|dna| baserecalibrator
        markduplicates -->|rna| splitncigar
        splitncigar -->|rna| baserecalibrator
        baserecalibrator -->|dna,rna| applybqsr
        applybqsr -->|dna,rna| samtools_stats
        samtools_stats -->|dna,rna| mosdepth
    end

    subgraph variant_calling [Variant Calling (parallel)]
        vc_fork[ ]
        mutect2[Mutect2]
        strelka[Strelka2]
        sage[SAGE]
        vc_join[ ]

        vc_fork -->|dna,rna| mutect2
        vc_fork -->|dna,rna| strelka
        vc_fork -->|dna,rna| sage
        mutect2 -->|dna,rna| vc_join
        strelka -->|dna,rna| vc_join
        sage -->|dna,rna| vc_join
    end

    subgraph normalization [Normalization & Annotation]
        vt_decompose[VT Decompose]
        vt_normalize[VT Normalize]
        ensemblvep[Ensembl VEP]

        vt_decompose -->|dna,rna| vt_normalize
        vt_normalize -->|dna,rna| ensemblvep
    end

    subgraph consensus [Consensus & Filtering]
        vcf2maf[vcf2MAF]
        run_consensus[Consensus]
        maf_filtering[MAF Filtering]

        vcf2maf -->|dna,rna| run_consensus
        run_consensus -->|dna,rna| maf_filtering
    end

    subgraph realign [Realignment (RNA)]
        maf2bed[MAF2BED]
        extract_reads[Extract Reads]
        hisat2[HISAT2]
        markdup_re[MarkDuplicates]
        splitncigar_re[SplitNCigarReads]
        bqsr_re[BQSR]
        varcall_re[Variant Calling]
        norm_re[Normalization]
        annotate_re[Annotation]
        consensus_re[Consensus]
        filter_re[MAF Filtering]

        maf2bed -->|realignment| extract_reads
        extract_reads -->|realignment| hisat2
        hisat2 -->|realignment| markdup_re
        markdup_re -->|realignment| splitncigar_re
        splitncigar_re -->|realignment| bqsr_re
        bqsr_re -->|realignment| varcall_re
        varcall_re -->|realignment| norm_re
        norm_re -->|realignment| annotate_re
        annotate_re -->|realignment| consensus_re
        consensus_re -->|realignment| filter_re
    end

    subgraph reporting [Reporting]
        rna_filter[RNA MAF Filtering]
        rna_filter -->|rna,realignment| multiqc
        multiqc[MultiQC]
        report_out[ ]

        multiqc -->|rna,realignment| report_out
    end

    %% Inter-section edges
    maf_filtering -->|realignment| maf2bed
    samtools_merge -->|dna,rna| markduplicates
    mosdepth -->|dna,rna| vc_fork
    vc_join -->|dna,rna| vt_decompose
    ensemblvep -->|dna,rna| vcf2maf
    filter_re -->|realignment| rna_filter
    maf_filtering -->|rna| rna_filter

CLI command

nf-metro render examples/topologies/foldback_exit_peeloff.mmd -o foldback_exit_peeloff.svg

Rendered map