一 。how Lordec maps the long reads to DeBruijn Graph
hello,
I would like how LorDEC maps long reads to debruijn graph. After construction of deBruijn graph of short reads ，how map the set of erroneous long reads to DeBuijn graph. it's not clear in the paper.
can you help me please?
Thank you for your response.
As far as I understand, after forming DBG graphs from short reads (SR),the use and store data in GATB library which allows to traverse any path in the graph and to get the sequence of any node. also PacBio long reads (LR) are divided to k-mer which will be compared (traversed) to the k-mer in the DBG of SR.
They used solid k-mer as anchor to correct PacBio reads
We found that if we additionally require that for a k-mer to be considered solid, it must also have at least one incoming and at least one outgoing arc 我们发现，如果我们额外要求一个k-mer被认为是强的 ，它也必须至少有一个传入和至少一个传出弧
how they correct the reads?
Consider the k-mers of a long read starting at position 1,2,3, … : some k-mers belong to the graph and are solid, while others do not and are weak. Basically, solid k-mers are expected to be correct, while weak ones suspectedly include sequencing errors and require a correction. Solid k-mers are entry points in the DBG, and LoRDEC corrects a region made of weak k-mers by finding the best path in the DBG between the solid k-mers bordering this region. Sometimes, an LR has no solid k-mer, in which case, LoRDEC marks it as such in the output and skips it.
The idea here is traversing not mapping (as I understand ) for more about traversing graph traverse
and here explanation about how it works
http://ivory.idyll.org/blog/2015-wok-error-correction.html
and here is a paper talking about the mapping of sequence to DBG
Read mapping on de Bruijn graphs
二。And LORMA? have you an explanation about LORMA?
It is divided into two phases :
- first using lordec with different k-mer to self-coorect the long
- reads second further correction with the multiple alignment technique by LoRMA
