Fig. 3

Multidimensional scaling (MDS) analysis of the transcriptional responses of clone G to temperature changes. A non-metric MDS analysis was applied to obtain a global view of similarities or dissimilarities in the transcriptional responses of the D. pulex clone G to temperature changes. For this purpose, the Euclidian distance between all transcriptomic data (i.e., transcriptional responses, which were normalized to either 20 °C acclimation or 20 °C controls) were scaled to three dimensions. Coordinate 1 of the MDS analysis shows a clear separation between the transcriptional responses to acute heat stress and temperature acclimation. The transcriptional responses to 2, 4, and 8 h of heat stress were different (coordinates 2 and 3) such as the responses to 10 °C, 20 °C, and 24 °C acclimation (coordinate 2)