Clustering of orientation genes. Hierarchical clustering of individual butterflies (top) based on expression profiles of the 40 regulated genes expressed as heat maps (below). Animal ID code for clustering is as depicted in Table 1. Bootstrap analysis provides confidence values at the nodes. The heat maps show estimated gene expression levels (red upregulated; green downregulated). The genes have been ordered according to k-means clustering.
Zhu et al. BMC Biology 2009 7:14 doi:10.1186/1741-7007-7-14