By default, the column shows the ratio of expression of a gene in
different tissues to the expression of the gene overall. A gene that is more highly
expressed in a tissue is colored red, and a less expressed gene is shown in
green. Values are colored on a logarithmic scale.
Black indicates that a gene is neither over- nor under-expressed in the tissue.
Uncolored boxes (white on most browsers) represent missing data.
While admittedly somewhat counter-intuitive, these conventions are standard
in gene expression datasets (from microarray technology).
Column Configuration
These options are available on the Configuration page,
which can be accessed via the configure button in the top menu.
Absolute expression values: The display can be configured to show
absolute expression values rather than ratio values. To toggle the display,
select the absolute option from the values pulldown menu.
Absolute expression values
are shown in shades of gray, with higher expression levels shown in lighter
shades. As with ratio values, absolute values are colored on a logarithmic
scale.
Color scheme: Color-blind users can switch the coloring scheme from red/green to
yellow/blue via the Expression ratio colors pulldown menu at the top
of the Configuration page.
Tissues: By default, only selected tissues are shown.
To display all 53 tissues, choose all from the pulldown menu.
Brightness: To increase or decrease the brightness of the expression colors,
edit the number in the column's brightness text box. Values greater
than 1.0 increase the brightness, while those less than 1.0 dim the color.
Methods
A brief summary of the GTEx gene expression methods is available on the related
browser
track description.
For more information about GTEx tissue sample collection, RNA-seq and expression
analysis methods, see the GTEx Portal
documentation page.
Credits
The data for this column was produced and analyzed by the members of the GTEx Consortium
and the GTEx Laboratory, Data Analysis, and Coordinating Center (LDACC) at the Broad Institute.
and are available by download from the
GTEx Portal.