[maker-devel] Maker not predicting many genes

[Carson Holt]

You also need to look at the contigs in a browser like apollo.  That will allow you to see both the predictions and the evidence in context.  You can then see if genes are being dropped because they are only being supported by single exon evidence, they have no evidence support whatsoever, or if they are being excluded because of UTR overlap.  That last one is a common problem for fungi when using assembled mRNA-seq reads.  Fungi genes are so close that they often overlap in the UTR.  As a result, mRNA-seq assemblers falsely asseble neighboring genes into single transcripts.  The result is really long UTR on some of your gene models that force other models to be excluded.  If this is the case, rerun something like trinity with the jacquard clip option set  to avoid transcript fusion.  Then set correct_est_fusion=1 in the MAKER control files to get those long false UTR’s clipped off.

If it is a lack of evidence overlap, make sure you provided minimum 1 proteome from a related species to the protein= option.  At least 2 proteomes are recommended though (these are not proteins from the same species but rather complete proteomes from related species).  Also comprehensive databases like UniProt/Swiss-prot are not sufficient on their own, but can supplement the other proteome data.  Also are you providing EST data?  Note that EST/mRNA-seq data without a proteome from a related species is also not siufficient (because both quality and how comprehensive EST/mRNA-seq databsases are can vary so widely, and may only capture as little as 30% of the genes).

Another thing that comes into play are single exon evidence.  In anything but fungi, single exon evidence is mostly caused by spurious alignments.  But fungi have so many single exon genes, that this is not the case for them.  Make sure single_exon=1 is set to allow that evidence to be kept, and set the length of single exon evidence to keep to something like 250 bp.

Thanks,
Carson






From: "Valero Jimenez, Claudio" <claudio.valero at wur.nl<mailto:claudio.valero at wur.nl>>
Date: Monday, February 17, 2014 at 2:23 AM
To: "'maker-devel at yandell-lab.org<mailto:'maker-devel at yandell-lab.org>'" <maker-devel at yandell-lab.org<mailto:maker-devel at yandell-lab.org>>
Subject: Maker not predicting many genes

Dear list,

I’m trying to annotate a fungal genome, and I’m surprised that Maker does not predict many genes (3697). I have trained SNAP and followed all the tutorials available. Ab initio predictors are able to predict between 8000-10000 genes. It is something that I have in the configuration file that is wrong?? I attach the ops file and the SOBA summary of the annotation.

Regards,

Claudio


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://yandell-lab.org/pipermail/maker-devel_yandell-lab.org/attachments/20140217/d8a9d19c/attachment-0003.html>