Figure 4

No evidence for nonsense-mediated decay in reducing neo-Y transcript abundance. (a) Neo-Y FPKM levels for transcripts with intact ORFs, transcripts containing a PTC and transcripts containing a frame-shift mutation only (and no PTC). Transcript levels for both classes of putative non-functional genes were significantly decreased, compared to those with intact ORFs (Wilcoxon test: W = 132628, p < 0.001 and W = 234562, p < 0.001). (b) Transcript abundance of the neo-Y in males, relative to the neo-X homolog in females, as a function of the length of the 3'UTR (estimated as the sum of the corresponding neo-X UTR length, plus the distance from the first PTC to the end of the CDS).