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Let’s create an NEW interactive session on the HPC:

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Alternative approach to create a conda env and install tools (we are not doing this - this just for your information) - installing all tools at once (slower option!)

Prepare the following environment.yml file:

Code Block
name: ONTvariants_mapping
channels:
  - conda-forge
  - defaults
  - bioconda
dependencies:
  - samtools=1.20
  - minimap2=2.28

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As you have seen, we can search at anaconda.org for other tools that we might be interested to use.

Remember, if you run into compatibility issues or errors, you can always create a new conda environment for the tool of interest. NOTE: you can switch between conda environements as follows:

Code Block
conda activate ONTvariants_QC
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conda deactivate
conda activate ONTvariants_mapping
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Code Block
#!/bin/bash -l
#PBS -N run2_mapping
#PBS -l select=1:ncpus=8:mem=16gb
#PBS -l walltime=72:00:00
#PBS -m abe

cd $PBS_O_WORKDIR

conda activate ONTvariants_mapping

###############################################################
# Variables
###############################################################
FASTQ='/work/training/ONTvariants/runs/run1_QC/SRR17138639_1_porechop_abi_chopper_q10_300b.fastq'
GENOME='/work/training/ONTvariants/data/chr20.fasta'
SAMPLEID='SRR17138639'
GENOMEID='chr20'
###############################################################

#STEP1: Mapping preprocessed reads with minimap2 onto reference genome
minimap2#minimap2 -t 8 -a $GENOME $FASTQ | awk '$3!="*"'  > ${SAMPLEID}_mapped_${GENOMEID}.sam
minimap2 -t 8 -a $GENOME $FASTQ > ${SAMPLEID}_mapped_${GENOMEID}.sam

##STEP2: samtools - SAM to sorted BAM
samtools view -bS ${SAMPLEID}_mapped_${GENOMEID}.sam > ${SAMPLEID}_mapped_${GENOMEID}.bam
samtools sort -o ${SAMPLEID}_mapped_${GENOMEID}.sorted.bam ${SAMPLEID}_mapped_${GENOMEID}.bam
samtools index ${SAMPLEID}_mapped_${GENOMEID}.sorted.bam

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To visualise the mapped reads (sorted BAM file) using IGV (see below), first we need to connect to the HPC using FileFinder:

NOTE: To proceed, you need to be on QUT’s WiFi network or signed via VPN.

To browse the working folder in the HPC type in the file finder:

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