Visualization of eQTL mapping result
- As traditional QTL mapping, expression Quantitative Trait Locus (eQTL) mapping tries to
find genomic variation to explain expression traits.
One difference between eQTL mapping and traditional QTL mapping is that, traditional
mapping study focuses on one or a few traits, while in most of eQTL studies,
thousands of expression traits will be analyzed and thousands of QTLs will be declared.
eQTL analysis is to study the relationship between genome and transcriptome.
We will never get all benefit from such systemic investigation until a complete set of
eQTL mapping results can be presented as a single unit.
As we will see, SVG technology allows us to display thousands of
genetic features involved in typical expression QTL studies within the limit of computer screens. In the meanwhile, massive amount of genome annotation entries can be superimposed
onto them and displayed as users' request.
view plot tab on top of this page,
we will present 2-D plots to visualize eQTL mapping results in
yeast and mice.
A toy example
illustrates many important features of the visualization.
This site provides a web-based service to transform any user provided QTL mapping results to a 2-dimensional plot.
In order to do that, however, users need first convert their results to certain
format that our program can handle as described in
prepare plot tab.
All relevant files can be downloaded from
What is SVG ?
- SVG, scalable vector graphics, is a XML application, which can be read and edited by human and common text editor;
- SVG graphics do NOT lose any quality if they are zoomed or resized;
- Every element and every attribute in SVG files can be animated;
Dynamic displaying information allows complex and huge amount of annotation applied to 2-D graphics.
- Plug-in for Internet Explorer can be download from
It parses text files (xml actually), displays image in the browser and responses to user operations. FireFox 1.5 starts to offer native support for SVG since 2006. However, such support is still rather limited. SVG in this site have been designed and tested to work with Adobe SVG viewer 3.0. They do not work properly with FireFox 1.5
- Bioinformatics resources using SVG, a webpage by Christopher
Lewis can be found