Truncated/duplicated genes in Metagenome Assembled Genomes (MAGs) from ONT+Illumina hybrid assembly
I have performed a metagenome assembly on a single sample using both Illlumina and ONT reads (average q-score 10) with
opera-ms. Then contigs were binned using
metaWRAP was used for bin refinement. From this sample I have obtained 22 good quality MAGs with a
completness > 70% and contamination < 5%.
The problem that I am facing right now is the presence of truncated/duplicated genes which are probably caused by false frameshifts introduced by ONT reads. I tried pilon to fix these sequencing errors but because of the low coverage, pilon did not solve the problem.
Also, It seems that the annotation pipelines can be more or less sensitive to this kind of problems. For example, the same MAG was annotated with two different pipeline:
prokka (metagenome mode). With RAST, the rubisco gene (rbcL) was splitted in 4 fragments, while with prokka the same gene was represented by 2 fragments.
My question is: are you aware of any annotation pipeline for MAGs that is less sensitive to false frameshifts introduced by sequencing errors? Perhaps an annotation pipeline that make use of a user-defined database of reference genomes (lucky for me my MAGs belong to taxa with a good number of genomes from isolated strains).
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