This is a test version of Biostars. For the public version, visit https://www.biostars.org.
How many read files I can use in tophat in the same run?

Good morning friends,

Supposing I have and experiment with 10 samples and each with just sra file. In tophat -r 20 test_ref reads_1.fq reads_2.fq syntax I should mention all of my fastq files? If yes, may you please tell me the order of files. I mean for example I should type reads_1.fq -> reads_10.fq?

Thanks a lot

rna-seq tophat

Run tophat on each sample separately (or write a simple bash script with a list of fastq file names as input and specify different output directory for each of them). In case of paired-end reads_1.fq and reads_2.fq defines for Right and Left.

1 answer

Each sample must be aligned independently. You can not give tophat all of the files for all of the samples at one time and get multiple output files.

Thanks Devon,

Sorry

I placed the orf_coding.fasta (my reference genome) in the bowtie2 file and indexed the genome in the same bowtie2, and run this syntax but error,

May you please tell me a solution?

[izadi@lbox161 bowtie2-2.2.5]$ $TOP/tophat -r 20 orf_coding.fasta SRR1944914_trimmed.fastq SRR1944926_trimmed.fastq

[2015-09-01 10:27:50] Beginning TopHat run (v2.1.0)
-----------------------------------------------
[2015-09-01 10:27:50] Checking for Bowtie
          Bowtie version:     2.2.5.0
[2015-09-01 10:27:50] Checking for Bowtie index files (genome)..
Error: Could not find Bowtie 2 index files (orf_coding.fasta.*.bt2)
[izadi@lbox161 bowtie2-2.2.5]$ $TOP/tophat -r 20 orf_coding.fasta SRR1944914_trimmed_unmapped.fastq SRR1944926_trimmed_unmapped.fastq

[2015-09-01 10:29:01] Beginning TopHat run (v2.1.0)
-----------------------------------------------
[2015-09-01 10:29:01] Checking for Bowtie
          Bowtie version:     2.2.5.0
[2015-09-01 10:29:01] Checking for Bowtie index files (genome)..
Error: Could not find Bowtie 2 index files (orf_coding.fasta.*.bt2)
[izadi@lbox161 bowtie2-2.2.5]$

This part of the error message should tell you what to fix:

Error: Could not find Bowtie 2 index files (orf_coding.fasta.*.bt2)

Sorry, but after indexing there are coding.1.bt2, coding.2.bt2, coding.3.bt2, coding.4.bt2, coding.rev.1.bt2 and coding.rev.2.bt2.

and orf_coding.fasta in bowtie2 file. Then what I should provide?

Then you need to write coding rather than orf_coding.fasta.

Thanks a lot Devon, you saved me I was getting mad since yesterday.

Log in to answer this question.