Fig. 3

Characterization of small RNAs and piRNA clusters from different C. gigas samples. a Sequence reads without annotation produce a significant ping-pong signature (top row of bars, only Z-scores for 10 bp 5′ overlap are shown). The number of ping-pong reads per million bootstrapped reads (middle row of bars), and the number of clustered reads (bottom row of bars) differs considerably across the samples. Heatmap shows the differential expression of the top 100 piRNA clusters in terms of maximum rpm coverage. Different classes of piRNA clusters are expressed during oyster development and in adult somatic tissues (bottom). Error bars indicate standard deviation. b Transposon composition of piRNA clusters belonging to four different classes. c Representation of transposons in the genome of C. gigas, plotted by divergence [%] from transposon consensus. d Representation of transposons within piRNA clusters of C. gigas, plotted by divergence [%] from transposon consensus. e Prominent transposons that are enriched or depleted in C. gigas piRNA clusters