Processing another sample with TopHat and HTSeq

Let’s script this!

Type:

cd ~/rnaseq/
module load Trimmomatic/0.32
cat > lung-tophat.sh <<EOF

and then paste this in:

module load Trimmomatic/0.32
module load TopHat2/2.0.8b
module load PySAM/0.6
module load HTSeq/0.6.1

# go to the 'rnaseq' directory in my home directory
cd ~/rnaseq

# subset the data sets (100,000 reads) - you don't want to do this
# on real data :)
head -400000 ~/RNAseq-model/data/ERR315326_1.fastq | gzip > lung_repl1_R1.fq.gz
head -400000 ~/RNAseq-model/data/ERR315326_2.fastq | gzip > lung_repl1_R2.fq.gz

# run Trimmomatic.  Here, the inputs are 'lung_repl1_R1.fq.gz' and
# 'lung_repl1_R2.fq.gz', and the outputs are 'lung_repl1_R1.qc.fq.gz'
# and 'lung_repl1_R2.qc.fq.gz'.
java -jar \$TRIM/trimmomatic PE lung_repl1_R1.fq.gz lung_repl1_R2.fq.gz \
  lung_repl1_R1.qc.fq.gz s1_se lung_repl1_R2.qc.fq.gz s2_se \
  ILLUMINACLIP:\$TRIM/adapters/TruSeq2-PE.fa:2:40:15 \
  LEADING:2 TRAILING:2 \
  SLIDINGWINDOW:4:2 \
  MINLEN:25

# now run Tophat!
# The inputs are the outputs of the previous Trimmomatic step.
# The outputs are going to be under the 'tophat_lung_repl1' directory.
tophat -p 4 \
    -G ~/RNAseq-model/Homo_sapiens/Ensembl/GRCh37/Annotation/Genes/genes.gtf \
    --transcriptome-index=$HOME/RNAseq-model/transcriptome \
    -o tophat_lung_repl1 \
    ~/RNAseq-model/Homo_sapiens/Ensembl/GRCh37/Sequence/Bowtie2Index/genome \
    lung_repl1_R1.qc.fq.gz lung_repl1_R2.qc.fq.gz

# count the hits by gene -- 'tophat_lung_repl1' is the main output,
# from Tophat.
htseq-count --format=bam --stranded=no --order=pos tophat_lung_repl1/accepted_hits.bam \
    ~/RNAseq-model/Homo_sapiens/Ensembl/GRCh37/Annotation/Genes/genes.gtf > lung_repl1_counts.txt
EOF

(Be sure to press the Enter or Return key after pasting this in!) This is called a ‘heredoc’ and it gives a way to write a shell script via copy-paste ;).

Next, type:

bash lung-tophat.sh

This will run all of the commands in the file ‘lung-tophat.sh’.

You can use the ‘nano’ editor to modify this file – type:

nano lung-tophat.sh

Next: Data analysis & differential expression

---

LICENSE: This documentation and all textual/graphic site content is licensed under the Creative Commons - 0 License (CC0) -- fork @ github. Presentations (PPT/PDF) and PDFs are the property of their respective owners and are under the terms indicated within the presentation.

---