Figure 5

piRNA mapping pattern in SVA and LTR1 elements. (A) Two ping-pong models. Based on ping-pong models proposed in mouse and Drosophila, two types of ping-pong signature are examined: sense ping-pong signature (SPS) and antisense ping-ping signature (ASPS). piRNAs mapped to the sense and antisense strand of an ME are shown as black and grey solid boxes, respectively. Red and green arrows indicate the diagnostic base for SPS and ASPS, respectively. (B) piRNA mapping pattern in LTR1 element. Top subplot shows density of piRNA matches to the consensus sequence of LTR1. The second and third row present mapping densities of piRNAs exhibit SPS (red bars) or ASPS (green bars), respectively. Peaks above and below the X-axis indicates piRNAs mapped to sense and antisense of the ME consensus, respectively. A diagram of the LTR1 consensus is shown at the bottom of the plot. (C) piRNA mapping pattern in SVA element. Top subplot shows density of piRNA matches to the consensus sequences of different SVA subfamilies (SVA_A-F). The second and third row present piRNAs exhibit SPS (red bars) or ASPS (green bars), respectively. Peaks above and below the X-axis indicates piRNAs mapped to sense and antisense of the ME consensus, respectively. A diagram of the SVA consensus is shown at the bottom of the plot. To demonstrate that the piRNAs match SVA-specific sequences, the sequence alignment was shown for SVA consensus, HERVK10 consensus, and the most abundant piRNA sequence. HERVK10 specific mutations are shown as bold letter in the alignment.