Cluster analysis of ncRNA expression profiles. Expression profiles of ncRNAs after k-means clustering (Additional file 2: Table S13). The x-axis shows sampling points I to V from left to right and the y-axis gives the expression strength in z-score transformed mean NPKM values of each replicate. Clusters are numbered and captioned with the count of included ncRNAs. Transcripts with a maximal NPKM value >100,000 are marked in orange and transcripts with a maximal NPKM value >1000 are marked in green.