sorry i'm still confused. Can I regard them as illumina/solexa? I mean; first "bwa aln", then "bwa sampe" ?
I read BWA manual. Seems for 454 longer reads, it's recommended to use BWA -BWASW, which only supports single-end reads.
Then what about 454 paired-end reads?Use bowtie? Also, 454 contain reads with variable length. Then how to deal with those very short reads? (I see some reads are only 10bp..) thx
@SRR000945.10444 E78I8DJ01CQCVG length=108
TGACTTTGTAATTTCCATATTTAAATTCCTTCATCTGATTTTCAGCTTCTCAGGGAAACCACCTAATATCCCTACCAGACAGTCATCTTTCATCTACTGAATAATTCC
+
AAABAAA====AABAAABBA@@AAAAAAABBBBBBBBB@@@@BBBBBBBBBBBAAAAAAABABBBBAAAAAAA@??AAAAAA???@=<<<@??????@@@@?==9995
@SRR000945.10446 E78I8DJ01A06WQ length=10
AACTCCCAGA
+
555=555995
@SRR000945.10447 E78I8DJ01A1GWE length=48
GCTCAAATAGTTATCTTCCCTGAGATGCCTCCCACTAACTCACAATCG
+
AAAA@@@A???AAAA??===?AAAAAA@@@?????@@@???????===
1 answer
BWASW-0.6 supports paired-end reads (as you know, BWA does not work with 454). Smalt is a good one. Bowtie2 should also work well, though I have not tried this myself. A caveat with Bowtie2 I found recently is that for a gap in a tandem repeat where the gap placement is uncertain, bowtie2 places the gap in a largely random position in the repeat (see this). This may pose challenges to some SNP/indel caller such as samtools which assume the mapper tries best to put the gap at the leftmost position. It is also fair to say this is a weakness of samtools. I used to try GMAP a few years ago. At that time, its performance was not as good as mappers more tuned for reads mapping, but this may be changed recently.
No, 454 reads have high homopolymer indel error rate. aln+sampe would not work well.
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the paired end vs single end reads are generated with the samse and sampe commands and I don't think the way you align aln or bwasw matters.
An obvious choice would be Newbler. If you can't use that, you could try GMAP. I don't have enough experience with the whole range of aligners to make a specific recommendation, though.
i am frankly surprised the 454 would report a 10bp read
see the edit plz......yeah, it does have 10bp read...or maybe this is not 454?
hi istvan; so for 454 paired-end reads, I simply regard them as illumina/solexa? I mean; first "bwa aln", then "bwa sampe" ?