Figure 4

plncRNA but not elncRNA loci are selectively constrained over rodent evolution. (A) Mouse-rat nucleotide substitution rate for elncRNA TIRs (median d_elncRNA-TIR = 0.161, green) and plncRNA TIRs (median d_plncRNA-TIR = 0.127, blue), and for neighboring putatively neutrally evolving sequence (ancestral repeats (ARs), white). Horizontal dashed line represents the neutral expectation (median d_AR = 0.165). (B) Mouse-rat nucleotide substitution rate for elncRNA loci (d_elncRNA-loci = 0.166, green) and plncRNA loci (d_plncRNA-loci = 0.159, blue), and ARs (white). (C) Mouse-rat nucleotide substitution rate for transcribed and spliced plncRNA exons (d_plncRNA-exon = 0.156, violet) and plncRNA introns (d_{plncRNA-intron} = 0.165, turquoise), and ARs (white). Two-tailed Mann–Whitney test, ***P < 0.001; **P < 0.01; *P < 0.05; NS, not significant.