Thanks Jen,
I have not had good luck with the Visualization feature. Using BAM files, it has worked once to produce a single histogram but mostly seems stuck preparing data for up to 3 hours with no production. Additionally,
once a graph is made how can one save the graph as a picture file; pdf, etc?
Best,
Trent
From: Jennifer Jackson [mailto:jen@bx.psu.edu]
Sent: Wednesday, May 30, 2012 3:17 PM
To: Fowler, Trent
Cc: galaxy-user@bx.psu.edu
Subject: Re: [galaxy-user] Genome Browser Histogram Visualization of Accepted Hits
Hi Trent,
Hiram's advice is very good for UCSC display (thanks Hiram!)
You most likely heard of converting BAM->SAM->Interval->BED->BigBED. But, Hiram is exactly correct - there will be a great loss of information (notably the full individual sequence data itself, as only the coordinates + variation will remain, plus the data
will be in BED6, which means no splicing, just global coordinates - you won't want this for RNA-seq).
Since you are examining RNA-seq data, I also wanted to remind you of the choice to use Trackster for visualization (top Galaxy menu -> "Visualization"). A local or custom reference genome can be used, histogram or full read display is possible, and deeply sequenced
areas can be "unpacked" in stages by using the visualization controls (really nice). Other features such as drag and drop composite track creation, new datasets from selects within Trackster (to feed more analysis), strand coloring, etc. are fairly recent
enhancements (see:
http://wiki.g2.bx.psu.edu/DevNewsBriefs/2012_03_12#Galaxy_Track_Browser_.28GTB.29
http://wiki.g2.bx.psu.edu/DevNewsBriefs/2012_05_11#Galaxy_Track_Browser_.28GTB.29). More undocumented (so far!) features are added all the time, so good to experiment. A new paper is in the works that will cover the details. And there will be tutorials,
screencasts, etc. later on, but for now during the active development cycle, just using it is best and is pretty intuitive. We're interested in what you like or wish was added (this is true to everyone reading this!). No promises, but is good to get feedback!
If there is a particular UCSC track (or another source mapped to same reference genome) that you wish to compare your data against, it could be imported into Galaxy and added to your Trackster visualization session. There are no known limits on data size/depth
- only the general Galaxy dataset file size limit of 50G (applies to all datasets) - although I suppose an extreme corner case could probably be devised/uncovered. The point is that a routine RNA-seq experiment shouldn't present a problem. Special tuning
to speed up and handle depth has been a big area of recent development activity. If you do run into issues with Trackster, feel free to ask questions (I'll probably ask you to send a share link to the visualization on the pubic main Galaxy instance and bring
Jeremy into the discussion if the solution is not clear).
Please let us know if you need more help,
Jen
On 5/29/12 11:57 AM, Fowler, Trent wrote:
Hello,
I am attempting to run accepted hit data from Tophat output into the UCSC Genome Web Browser for visualization of sequencing hits in specific genes. However, the BAM files yield tiles and are too large to present through the browser. Is
there a better file format to convert to that would allow better visualization such as histograms?
From word of mouth, I have been told to convert BAMs to BEDs and put BED files through the browser. However, I notice that Galaxy does not have an option for this and the oft used BEDtools appears to involve writing code, which is above
my computer abilities.
Any tips or solutions on how to obtain histograms from sequencing data would be very welcome.
Thanks
Trent Fowler
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