Fig. 5

Relation between percentages of genes with tissue-specific differential expression by tissue and classification thresholds. a–d show the relationship between tissue-specific differential expression, classification methods, and classification thresholds. Regardless of the classification method, all catalogues are enriched in genes expressed in the CNS at much higher levels than in tissues with fewer or none synapses. Notice that increasing the threshold did not result in an increment of the proportion of genes differentially expressed in tissues other than the CNS. a k-NN catalogues, b Random Forest catalogues, c SVM catalogues, d consensus catalogues. The threshold values are shown in the horizontal axis, with 0 corresponding to the initial set of genes to be classified. Each colored line corresponds to one of the five analyzed tissues according to the color code shown at the bottom