Fig. 4
Long-term phenotypic alterations after infection with ZIKV. A The number of mature neurons (NeuN +) per tissue area (DAPI +) was quantified (NeuN + /mm2) in the OHC of the control and ZIKV PE243 or SPH2015 infected groups 5, 7 and 10 days p.i.. Samples outside the range between the lower and upper quartiles of the median of their respective groups (interquartile range) were excluded from the analysis. Two-way ANOVA test was used followed by Tukey’s multiple comparison test. Data were expressed as mean ± standard deviation. *P < 0.05; ****P < 0.0001. Number of animals = CTRL 5 (13), CTRL 7 (10), CTRL 10 (8), PE243 5 (10), PE243 7 (11), PE243 10 (8), SPH 5 (12), SPH 7 (10), SPH 10 (8). B Fluorescence intensity (FI) of the epigenetic marker H3K4me3 was estimated in mature neurons in the OHC of the control and infected with ZIKV SPH2015 and PE243 groups at 5, 7 and 10 days p.i.. These values were normalized by the number of positive neurons for this mark (NeuN + H3K4me3 +) (n ≥ 8). Values outside the range between the lower and upper quartiles of the median of their respective groups (interquartile range) were excluded from the analysis. Two-way ANOVA test was used followed by Tukey’s test of multiple comparisons and data were expressed as mean ± standard deviation. *P < 0.05; ***P < 0.001; ****P < 0.0001. Sample size = CTRL 5 (6), CTRL 7 (6), CTRL 10 (4), PE243 5 (5), PE243 7 (4), PE243 10 (6), SPH 5 (6), SPH 7 (5), SPH 10 (4). C Micrographs (60 ×) obtained from OHC 10 days p.i.. Cell nuclei are stained in blue (DAPI), mature neurons in red (NeuN) and H3k4me3 in green. Scale bar = 10 µm. In detail, a digital zoom (2X) of typical H3k4me3 staining (scale bar = 5 µm)