Hello, there,
I am curious how the mapping score is calculated by bowtie and wonder what is the general cutoff to keep a valid read from bowtie output.
The bowtie manual says that mapping quality <10 might suggest the multiple alignments.
What I've noticed is that some low complexity reads give pretty low mapping quality scores. But they are not mapped to multiple sites at all.
For examples, both of the following sequences have mapping quality of 6, even though one contains almost a polyG sequence:
NS500253:4:H14JDBGXX:1:22111:1653:3874 147 NC_010451.3 5426974 6 144M = 5426886 -232 GCGGGAGAAGTCCCGGCAGAATTGAAGCTGCTTCTTTGAATTTGCAATTCAACATGACATTCACCACGGAACTGGCAAAAAGAGGGCTTAACCTCTGTCTTTAGATTTACAGTCTAATGCTTACTCAGCCATTTTACCTATGTT F<F.<<FF7FFAFF)F<FF7FA7AFFAFFAFAFFFF7FFFF<<FFFFF<FAFFFAFFAF7FFFF<FF.FFFFFF7FFFAFFFFF)F.AFFFFFFFFFFFFFFFFFFF.FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFAAAAAA AS:i:0 XS:i:-5 XN:i:0 XM:i:0 XO:i:0XG:i:0 NM:i:0 MD:Z:144 YS:i:0 YT:Z:CP
NS500253:4:H14JDBGXX:1:22111:4914:4835 73 NC_010459.4 37759824 6 151M = 37759824 0 ATTTTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG <AAAAF.AFFFFFFFFFFAFFFFFFFFAFAFFFFAFFFFFFFAFFAFAAFAFFAFFFF7FFAFFFFAFFFFFFFAAFFAAFFFFA7FAFFFAF7AF.FA<FFF..F.AAFFFAFFFFFFAFFF7FFAFF7FAF<<.FAFA.FFFF<F<A.F AS:i:-5 XS:i:-6 XN:i:5 XM:i:5 XO:i:0 XG:i:0 NM:i:5 MD:Z:0N0N0N0N0N146 YT:Z:UP
Thanks for any input
I am curious how the mapping score is calculated by bowtie and wonder what is the general cutoff to keep a valid read from bowtie output.
The bowtie manual says that mapping quality <10 might suggest the multiple alignments.
What I've noticed is that some low complexity reads give pretty low mapping quality scores. But they are not mapped to multiple sites at all.
For examples, both of the following sequences have mapping quality of 6, even though one contains almost a polyG sequence:
NS500253:4:H14JDBGXX:1:22111:1653:3874 147 NC_010451.3 5426974 6 144M = 5426886 -232 GCGGGAGAAGTCCCGGCAGAATTGAAGCTGCTTCTTTGAATTTGCAATTCAACATGACATTCACCACGGAACTGGCAAAAAGAGGGCTTAACCTCTGTCTTTAGATTTACAGTCTAATGCTTACTCAGCCATTTTACCTATGTT F<F.<<FF7FFAFF)F<FF7FA7AFFAFFAFAFFFF7FFFF<<FFFFF<FAFFFAFFAF7FFFF<FF.FFFFFF7FFFAFFFFF)F.AFFFFFFFFFFFFFFFFFFF.FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFAAAAAA AS:i:0 XS:i:-5 XN:i:0 XM:i:0 XO:i:0XG:i:0 NM:i:0 MD:Z:144 YS:i:0 YT:Z:CP
NS500253:4:H14JDBGXX:1:22111:4914:4835 73 NC_010459.4 37759824 6 151M = 37759824 0 ATTTTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG <AAAAF.AFFFFFFFFFFAFFFFFFFFAFAFFFFAFFFFFFFAFFAFAAFAFFAFFFF7FFAFFFFAFFFFFFFAAFFAAFFFFA7FAFFFAF7AF.FA<FFF..F.AAFFFAFFFFFFAFFF7FFAFF7FAF<<.FAFA.FFFF<F<A.F AS:i:-5 XS:i:-6 XN:i:5 XM:i:5 XO:i:0 XG:i:0 NM:i:5 MD:Z:0N0N0N0N0N146 YT:Z:UP
Thanks for any input