  Background: The eMouse Atlas of Gene Expression (EMAGE) is an online resource
that publishes the results of in situ gene expression experiments on the
developmental mouse. The resource provides comprehensive search facilities, but
few analytical tools or visual mechanisms for navigating the data set. To deal
with the missing visual navigation, this paper explores the application of
sunburst and icicle visualizations within EMAGE. Results: A prototype solution
delivered a simple user interface that helps the user query EMAGE and generate
a sunburst/icicle diagram. An evaluation featuring test subjects from the EMAGE
staff studied the visualizations and provided a range of suggested
improvements. Moreover the evaluation discovered that in addition to providing
a visual means of walking through the data, when grouped, the sunburst delivers
an interactive overview that assists with analysing sets of related genes.
Conclusions: The sunburst and icicle visualizations have been shown to be
effective tools for summarising gene expression data. The sunburst with its
space saving radial layout was found especially useful for providing an
overview of gene families or pathways. Work is ongoing to integrate these
visualizations into EMAGE.
