chipseq brain-chipseq-dm6 track hub Track Settings
 
chipseq tracks for brain-chipseq-dm6 track hub

Maximum display mode:       Reset to defaults   

Type of graph:
Track height: pixels (range: 11 to 128)
Data view scaling: Always include zero: 
Vertical viewing range: min:  max:   (range: 0 to 127)
Transform function:Transform data points by: 
Windowing function: Smoothing window:  pixels
Negate values:
Draw y indicator lines:at y = 0.0:    at y =
Graph configuration help
Select views (Help):
spp brainchipseq signalview ▾       chipseq brainchipseq peakview       macs2 brainchipseq signalview ▾      
Select subtracks by antibody and npeaks:
 All antibody cp190  shep  suhw  mod 
npeaks
4758 
18682 
11517 
1330 
3437 
7660 
4744 
936 
Select subtracks further by: (select multiple categories and items - Help)
algorithm:
run label:

List subtracks: only selected/visible    all    ()
  antibody↓1 npeaks↓2 algorithm↓3 run label↓4   Track Name↓5  
dense
 cp190  18682  spp  cp190  cp190.spp   Data format 
full
 Configure
 cp190  18682  spp  cp190  cp190.spp smoothed_enrichment   Data format 
dense
 cp190  7660  macs2  cp190  cp190.macs2   Data format 
full
 Configure
 cp190  7660  macs2  cp190  cp190.macs2 control   Data format 
full
 Configure
 cp190  7660  macs2  cp190  cp190.macs2 treatment   Data format 
dense
 mod  4758  spp  mod  mod.spp   Data format 
full
 Configure
 mod  4758  spp  mod  mod.spp smoothed_enrichment   Data format 
dense
 mod  936  macs2  mod  mod.macs2   Data format 
full
 Configure
 mod  936  macs2  mod  mod.macs2 control   Data format 
full
 Configure
 mod  936  macs2  mod  mod.macs2 treatment   Data format 
dense
 shep  11517  spp  shep  shep.spp   Data format 
full
 Configure
 shep  11517  spp  shep  shep.spp smoothed_enrichment   Data format 
dense
 shep  4744  macs2  shep  shep.macs2   Data format 
full
 Configure
 shep  4744  macs2  shep  shep.macs2 control   Data format 
full
 Configure
 shep  4744  macs2  shep  shep.macs2 treatment   Data format 
dense
 suhw  1330  macs2  suhw  suhw.macs2   Data format 
full
 Configure
 suhw  1330  macs2  suhw  suhw.macs2 control   Data format 
full
 Configure
 suhw  1330  macs2  suhw  suhw.macs2 treatment   Data format 
dense
 suhw  3437  spp  suhw  suhw.spp   Data format 
full
 Configure
 suhw  3437  spp  suhw  suhw.spp smoothed_enrichment   Data format 
    
Assembly: D. melanogaster Aug. 2014 (BDGP Release 6 + ISO1 MT/dm6)

ChIP-seq tracks

This set of tracks is used for inspecting results from ChIP-seq experiments that have been run through various configured peak-callers. It includes signal tracks as well as called peak tracks.

Overview

These chipseq tracks have been generated by each peak caller. All peak-callers create a track of called peaks. Some of them also create normalized signal tracks, and those are shown here as well. These normaizlied tracks make it easier to diagnose the quality of called peaks, since these signals are what the peak-caller "sees" when it's running.

These normalized tracks are scaled differently for each peak-caller, see below for details.

Peak-caller runs

Different algorithms give different results. So the pipeline generally runs multiple algorithms on the same data. Each run is uniquely described by its run label and its algorithm. Run labels are highly dependent on the experiment.

Selecting data

Checkbox matrix

Use checkboxes to show/hide data. Typically, the most meaningful variables have been incorporated into the checkbox matrix. For ChIP-seq experiments, this is usually antibody and celltype, but of course this will vary by experiment.

Filter menus

Underneath the checkbox matrix are drop-down menus. These show secondary ways of selecting data. The filters update when you make changes, so changing one filter will cause options to be grayed out in other filters if the data don't exist for an option.

algorithm will subset all tracks by algorithm. run label subsets track by the run label, which is highly dependent on the experiment.

The npeaks filter can be ignored. It's just a by-product of putting the peak counts in the list of tracks.

Other filters may be included on an experiment-by-experiment basis.

Showing/hiding peaks and signal

Look just above the checkbox matrix for the "Select views" section. These views are subsets of signal for each of the peak-callers that were used, plus one track for all peak-callers.

If you want to see signal, the signal view for the corresponding algorithm should be set to "full". If you want to see peaks, the peaks view should be set to "dense". If you want to disable something, change it to "hide".

See below for details on each algorithm's signal tracks.

Adjusting y-axes for signal

Each of the signal views (just above the checkbox matrix) can have its name clicked to change the settings for just that view. The most useful setting is "vertical viewing range", which sets the ymin/ymax values. By default this is set to values that work well across a wide range of experiments, but you may have to tweak this for your particular experiment.

Algorithm track details

algorithm code paper
macs2 code paper
spp code paper
sicer code paper
PePr code paper

spp

  • Signal track is log2 fold change (IP/control), where higher values indicate more enrichment in the IP.
  • Large blocks or plateaus of continuous high or low signal indicate no reads in control or IP. SPP appears to do this particularly with low-enrichment libraries.

macs2 and macs2_broad

  • "treatment" track is the MACS-scaled, 3'-shifted signal for the IP
  • "control" track is the MACS-scaled, smoothed signal for the control. MACS uses a multiple-window approach estimate the openness of local chromatin. This track shows the value for the window with the highest lambda value for each bp.

Contact [email protected] with questions.

PePr

PePr does not generate normalized signal tracks.

SICER

SICER is used for calling broad peaks.

  • "normalized" track shows SICER's internal normalization. The y-values of this track seem to be highly dependent on the windowsize and gapsize parameters.
  • "islands" track shows SICER's binning of strong signal into islands; these are used to call regions.

Config

The full config file is below. It was used to define peak-calling runs for the pipeline, and serves as a reference to connect together the IP and input for each run. You can ignore it for the most part, but it can be used to dig into the details of exactly what parameters and what samples went into each run:

differential: []
final_bam_ext: .trim.fastq.unique.nodups.bam
peak_calling:
- algorithm: macs2
  control:
  - LM49_input-brains
  label: shep
  treatment:
  - LM50_shep-brains
- algorithm: macs2
  control:
  - LM49_input-brains
  label: mod
  treatment:
  - LM51_mod-brains
- algorithm: macs2
  control:
  - LM49_input-brains
  label: suhw
  treatment:
  - LM52_suhw-brains
- algorithm: macs2
  control:
  - LM49_input-brains
  label: cp190
  treatment:
  - LM53_cp190-brains
- algorithm: spp
  control:
  - LM49_input-brains
  extra: --fdr=0.01
  label: shep
  treatment:
  - LM50_shep-brains
- algorithm: spp
  control:
  - LM49_input-brains
  extra: --fdr=0.01
  label: mod
  treatment:
  - LM51_mod-brains
- algorithm: spp
  control:
  - LM49_input-brains
  extra: --fdr=0.01
  label: suhw
  treatment:
  - LM52_suhw-brains
- algorithm: spp
  control:
  - LM49_input-brains
  extra: --fdr=0.01
  label: cp190
  treatment:
  - LM53_cp190-brains