Biology Reference
In-Depth Information
Fig. 2.
The signature algorithm requires as input a set of genes, some of which
are expected to be coregulated based on additional biological information such as
a common promoter binding motif or functional annotation. (a) The algorithm
proceeds in two steps: In the first step, this input seed is used to identify the con-
ditions that induce the highest average expression change in the input genes. Only
conditions with a score above some threshold are selected. In the second stage of
the algorithm, genes that are highly and consistently expressed over these condi-
tions are identified. The result consists of a set of coregulated genes together with
the regulating conditions, and is termed as “transcription module.” (b) The out-
put contains only the coregulated part of the input seed, as well as other genes that
were not part of the original input but display a similar expression profile over the
relevant conditions.
