Fig. 6

Integration with tissue data identifies disease-relevant alterations in piRNAs in neurons. a Heatmap and hierarchical clustering based on the TOP100 differentially expressed piRNAs in tissues (sorted by adjusted p-value). PD-patient tissues (salmon) are clearly separated from control-patient tissues (azure). b Venn diagrams of all upregulated and downregulated piRNAs in tissue and neurons. There are 70 shared piRNAs that may be suited as diagnostic markers. c Plot of cytosine content in all deregulated piRNAs over nucleotide positions 1 to 29 in tissue. In the first 10 nucleotides, cytosines are overrepresented in the upregulated piRNAs (green line) as compared to all piRNAs (dark red line). This phenomenon is not present in the downregulated piRNAs (blue line). d SINE- and LINE-derived piRNAs are enriched in the downregulated piRNA fraction in tissue. SINE- and LINE-derived piRNAs are enriched in the fraction of downregulated piRNAs as compared to their abundance in the genome, although this effect is only significant for LINE-derived piRNAs (two-sided chi-square test, p < 0.05)