GMOD

JBrowse Tutorial Programming for Biology 2014

This JBrowse tutorial was presented by Scott Cain at the Programming for Biology at Cold Spring Harbor Laboratory in October 2014 using JBrowse 1.11.5.

This tutorial assumes a Mac OS X computer with apache configured to allow UserDir (~username).

Contents

Things to add to future tutorials

Prerequisites

Prerequisites are installed by JBrowse automatically. A few things may fail to install (like legacy support for wiggle files), but that doesn’t matter.

Make sure you can copy/paste from the wiki.

It’s also very useful to know how to tab-complete in the shell.

It’s probably a good idea to use a browser like Chrome that has the ability to turn off caching while working on this tutorial. To do this in Chrome, with the browser open to the JBrowse page you’re working on, select Developer->Javascript Console from the View menu. In the console, click the “gear” icon (settings) and check the box labeled “Disable Cache”.

JBrowse Introduction

How and why JBrowse is different from most other web-based genome browsers, including GBrowse.

More detail: paper

JBrowse presentation

Setting up JBrowse

Getting JBrowse

cd ~/Sites
mkdir jbrowse_demo
cd jbrowse_demo
curl -O https://s3.amazonaws.com/jbrowse-tutorials/Prog_for_Bio_2014_JBrowse.zip #that's a capital "O" not a zero/zed.
unzip Prog_for_Bio_2014_JBrowse.zip
cd Prog_for_Bio_2014_JBrowse
unzip JBrowse-1.11.5.zip
mv JBrowse-1.11.5 jbrowse
cd jbrowse
./setup.sh

Starting Point

Visit in web browser:

http://localhost/~username/jbrowse_demo/Prog_for_Bio_2014_JBrowse/jbrowse/index.html

You should see a “Congratulations” page.

Basic Steps

There are four basic steps to setting up an instance of JBrowse:

  1. Load and format reference sequences
  2. Format data for tracks
  3. Configure direct-access tracks
  4. Index feature names

Features from a directory of files

Here, we’ll use the Bio::DB::SeqFeature::Store adaptor in “memory” mode to read a directory of files. There are adaptors available for use with many other databases, such as Chado and Bio::DB::GFF.

Config file: pythium-1.conf

{
  "description": "GMOD Summer School 2013 P. ultima Example",
  "db_adaptor": "Bio::DB::SeqFeature::Store",
  "db_args" : {
      "-adaptor" : "memory",
      "-dir" : ".."
   },
...

Specify reference sequences

The first script to run is bin/prepare-refseqs.pl; that script is the way you tell JBrowse about what your reference sequences are. Running bin/prepare-refseqs.pl also sets up the “DNA” track.

Run this from within the jbrowse directory (you could run it elsewhere, but you’d have to explicitly specify the location of the data directory on the command line).

cd ~/Sites/jbrowse_demo/Prog_for_Bio_2014_JBrowse/jbrowse
bin/prepare-refseqs.pl --gff ../scf1117875582023.gff

Refresh it in your web browser, you should new see the JBrowse UI and a sequence track, which will show you the DNA base pairs if you zoom in far enough.

Load Feature Data

Next, we’ll use biodb-to-json.pl to get feature data out of the database and turn it into JSON data that the web browser can use.

In this case, we have specified all of our track configurations in pythium-1.conf.

...
 
  "TRACK DEFAULTS": {
    "class": "feature"
  },
 
 "tracks": [
    {
      "track": "Genes",
      "key": "Genes",
      "feature": ["mRNA"],
      "autocomplete": "all",
      "class": "transcript",
      "subfeature_classes" : {
            "CDS" : "transcript-CDS",
            "UTR" : "transcript-UTR"
      }
    },
   ...
]

track specifies the track identifier (a unique name for the track, for the software to use). This should be just letters and numbers and - and _ characters; using other characters makes things less convenient.

key specifies a human-friendly name for the track, which can use any characters you want.

feature gives a list of feature types to include in the track.

autocomplete including this setting makes the features in the track searchable.

urltemplate specifies a URL pattern that you can use to link genomic features to specific web pages.

class specifies the CSS class that describes how the feature should look.

For this particular track, I’ve specified the transcript feature class.

Run the bin/biodb-to-json.pl script with this config file to format this track, and the others in the file:

bin/biodb-to-json.pl --conf ../pythium-1.conf

Refresh JBrowse in your web browser. You should now see a bunch of annotation tracks.

Index feature names

When you generate JSON for a track, if you specify "autocomplete" then a listing of all of the feature names from that track (along with feature locations) will also be generated and used to provide feature searching and autocompletion.

The bin/generate-names.pl script collects those lists of names from all the tracks and combines them into one big tree that the client uses to search.

bin/generate-names.pl -v

Visit in web browser, try typing a feature name, such as maker-scf1117875582023-snap-gene-0.26-mRNA-1. Notice that JBrowse tries to auto-complete what you type.

Features from GFF3 or BED files

We’re going to add a couple more tracks that come from a flat file, repeats.gff. To get feature data from flat files into JBrowse, we use flatfile-to-json.pl.

bin/flatfile-to-json.pl --trackLabel repeatmasker \
    --type match:repeatmasker --key RepeatMasker \
    --className generic_parent \
    --subfeatureClasses '{"match_part" : "feature"}' --gff ../repeats.gff
bin/flatfile-to-json.pl --trackLabel repeatrunner \
    --type protein_match:repeatrunner \
    --key RepeatRunner --className generic_parent \
    --subfeatureClasses '{"match_part" : "feature"}' --gff ../repeats.gff

Visit in web browser; you should see the two new RepeatMasker and RepeatRunner tracks.

BAM alignments

JBrowse can display alignments directly from a BAM file on your web server. Simply place the BAM file in a directory accessible to your web server, and add a snippet of configuration to JBrowse to add the track, similar to:

     {
        "label" : "bam_alignments",
        "key" : "BAM alignments",
        "storeClass" : "JBrowse/Store/SeqFeature/BAM",
        "urlTemplate" : "../../simulated-sorted.bam",
        "type" : "Alignments2"
      }

This can be added by either editing the data/trackList.json file with a text editor, or by running something like this at the command line to inject the track configuration:

echo '{
       "label" : "bam_alignments",
       "key" : "BAM alignments",
       "storeClass" : "JBrowse/Store/SeqFeature/BAM",
       "urlTemplate" : "../../simulated-sorted.bam",
       "type" : "Alignments2"
     }' | bin/add-track-json.pl data/trackList.json

BAM coverage

     {
        "label" : "bam_coverage",
        "key" : "BAM Coverage",
        "storeClass" : "JBrowse/Store/SeqFeature/BAM",
        "urlTemplate" : "../../simulated-sorted.bam",
        "type" : "SNPCoverage"
      }

Quantitative data

BigWig

JBrowse can display quantitative data directly from a BigWig file on your web server. Simply place the BigWig file in a directory accessible to your web server, and add a snippet of configuration to JBrowse to add the track, similar to:

     {
        "label" : "bigwig_bam_coverage",
        "key" : "BigWig - BAM coverage",
        "storeClass" : "BigWig",
        "urlTemplate" : "../../simulated-sorted.bam.coverage.bw",
        "type" : "JBrowse/View/Track/Wiggle/XYPlot",
        "variance_band" : true
      }

This can be added by either editing the data/trackList.json file with a text editor, or by running something like this at the command line to inject the track configuration:

echo ' {
       "label" : "bigwig_bam_coverage",
       "key" : "BigWig - BAM coverage",
       "storeClass" : "BigWig",
       "urlTemplate" : "../../simulated-sorted.bam.coverage.bw",
       "type" : "JBrowse/View/Track/Wiggle/XYPlot",
       "variance_band" : true
     } ' | bin/add-track-json.pl data/trackList.json

Variation Data

VCF tracks

JBrowse can also display VCF variation data directly from a VCF file on your web server that has been compressed with Heng Li’s bgzip and tabix. Simply place the .vcf.gz and .vcf.gz.tbi files in a directory accessible to your web server, and add a snippet of configuration to JBrowse to add the track, similar to:

      {
        "label" : "bam_variation",
        "key" : "VCF simulated variation",
        "storeClass" : "JBrowse/Store/SeqFeature/VCFTabix",
        "urlTemplate" : "../../simulated-sorted.vcf.gz",
        "type" : "HTMLVariants"
      }

This can be added by either editing the data/trackList.json file with a text editor, or by running something like this at the command line to inject the track configuration:

echo ' {
       "label" : "bam_variation",
       "key" : "VCF simulated variation",
       "storeClass" : "JBrowse/Store/SeqFeature/VCFTabix",
       "urlTemplate" : "../../simulated-sorted.vcf.gz",
       "type" : "HTMLVariants"
     } ' | bin/add-track-json.pl data/trackList.json

Faceted Track Selection

JBrowse has a very powerful faceted track selector that can be used to search for tracks using metadata associated with them.

The track metadata is kept in a CSV-format file, with any number of columns, and with a “label” column whose contents must correspond to the track labels in the JBrowse configuration.

The demo bundle contains an example trackMetadata.csv file, which can be copied into the data directory for use with this configuration.

cp trackMetadata.csv jbrowse/data

Then a simple faceted track selection configuration might look like:

   "trackSelector": {
       "type": 'Faceted',
   },
   "trackMetadata": {
       "sources": [
          { "type": 'csv', "url": 'data/trackMetadata.csv' }
       ]
   }

The jbrowse_conf.json file in the jbrowse directory already conveniently contains this stanza, commented out. Uncomment it, refresh your browser, and you should now see the faceted track selector activated.

JBrowse Features

Highlighting interesting things

To highlight a region, you can either right-click on a feature and select ‘highlight this’, or you can set the highlight explicitly to a certain genomic region by clicking “View -> Set highlight” in the menu bar.

Beginning in JBrowse 1.10.0 you can also highlight a region with the mouse by clicking the highlighter tool (next to the Go button) and clicking and dragging to highlight a region.

Opening local files

JBrowse can display GFF3, BAM, BigWig, and VCF+Tabix files directly from your local machine without the need to transfer any data to the server. Just use the “File -> Open” tool from the menu bar to add tracks using local files.

Combination tracks

Starting in version 1.10.0, users can define tracks that are combinations of the data in other tracks. The operations used to combine these tracks can be set operations (union, intersection, subtraction), arithmetic operations for quantitative tracks (addition, subtraction, multiplication, division), and/or masking operations to just highlight or mask some regions based on data in another track.

To add a combination track, select “File->Add combination track” from the menu bar, and drag existing tracks into the new combination track to start combining them.

Upgrading an Existing JBrowse

If the old JBrowse is 1.3.0 or later, simply move the data directory from the old JBrowse directory into the new JBrowse directory.

Common Problems

Future JBrowse Plans

See the accompanying slides (PDF)

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