Data search and visualisation

Efficient search via ontology-driven query expansion 

Expression Atlas uses ontology-driven search expansion to make your searching more efficient. The terms used to annotate samples are mapped to ontology terms from the Experimental Factor Ontology (EFO). Ontology mappings allow for much richer queries using the hierarchy within the ontology, for example, searching for lung carcinoma will return matches to the keyword and also results for different subtypes such as large cell lung carcinoma (Figure 3).

Figure 3 Expression Atlas provides ontology-driven query expansion.

Easy interpretation of results through heatmap visualisation

Gene expression results are visualised using heatmaps in which gene expression values are converted into a colour-scale image. This provides a visual representation of the expression of multiple genes across different biological conditions (Figure 4A) or of a single gene across different experiments and biological conditions (Figure 4B). We will look at these heatmaps in more detail in the section Searching and visualising data in Expression Atlas.

Figure 4 Visualisation of gene expression results through heatmaps.