Figure 5

Systematic interpretation. For systematic interpretation of large datasets, the comprised variance can be divisively split up in a "top-down" "by-trait" assessment shown in panel a: After regarding the variance between a small number of trait clusters (Figs. 2 and 3), the variance within each cluster is analyzed separately in the same way (Figs. 6 and 7 in the Additional file 1) until analyses consist of single traits. Thus, the top-down approach proceeds from the predominant variance to more subtle changes, answering the question which traits are different and which similar transcriptionally. In contrast, an agglomerative "bottom-up" approach will focus on few traits initially (panel b). These may stem from a single annotation (aspect, parameter) of special interest (e. g. alcohol consumption, Fig. 4). In further steps, the most interesting annotation (not necessarily representing large variance) is combined with other aspects to visualize their interaction.