Fig. 4

Sex-dependent alteration of core features in USVs of FMRP-deficient mice. (A) FMRP deficiency specifically leads to longer mean length of vocalizations in males. (B, C) Frequency distribution (%) of USV length shows opposite impacts in male (B) and female (C) pups. (D-F) The principal frequency of vocalizations remains similar across the groups. (G) In the absence of FMRP, only females exhibit a statistically more negative mean power in their USVs. (H, I) Frequency distribution analysis reveals that both sexes show a greater utilization of USVs with more negative power in FMRP-deficient pups. (J-L) The mean change in frequency of USVs does not appear to be affected by the FXS genotype in either sex (J), but frequency distribution analysis indicates wider delta use in the absence of FMRP in males (K) but not in females (L). (A, D, G, J) Single dots represent individual mice. Data are presented as min. to max. box plots with median and 25–75 percentile. Mann-Whitney U tests were performed, and p-values < 0.05 are indicated in the graphs. Full statistical details can be found in Suppl. Table 3. (B, C, E, F, H, I, K, L) Data are represented as a Gaussian curve fit (± CI) of the frequency distribution (%). Sample sizes: (A–L) +/y males N = 9, -/y males N = 14, +/+ females N = 7, +/- females N = 13 and -/- females N = 6