Fig. 4

Effects of pre- and peri-implantation ZIKV infection on mouse embryos. a Scheme of ZIKV infection in pregnant Ifnar^−/− mice. b Scheme of ZIKV infection of mouse blastocysts in vivo and propagation in vitro. c Number of blastocysts recovered from pregnant Ifnar^−/− mice infected in b. n = 9 MOCK, n = 10 ZIKV. d Immunostaining of ZIKV E and CAS3 in blastocysts infected in b. Scale Bar = 20 µm. e Percentage of recovered blastocysts staining positive and negative for ZIKV E infected in c. n = 15 MOCK, n = 18 ZIKV. f Quantification of ZIKV E and CAS3 among CDX2⁺ and CDX2^- cells from blastocysts infected in b. n = 3. g Quantification of ZIKV vRNA level in E10.5 embryos (upper) and placentas (lower) infected at E3.5 and E4.5 in a. n = 4 for MOCK embryos and placentas, n = 7 for E3.5 embryos and placentas, and n = 12 for E4.5 embryos, n = 15 for E4.5 placentas. h Whole-mount chromogenic immunohistochemistry for ZIKV E antigen (purple precipitate) in E10.5 embryos of Ifnar^−/− dams infected at E4.5 in a. Scale bar = 500 µm. n = 3. i Quantification of ZIKV vRNA level in heads of E10.5 embryos infected in a. n = 10 for MOCK, n = 13 for ZIKV. j Co-staining of SOX2 with ZIKV E in E10.5 embryonic brains infected in a. Scale bar = 50 µm. k Co-staining of CAS3and SOX2 in E10.5 embryonic brains infected in a. Scale bar = 100 µm. l Quantification of CAS3 + area in k. n = 6 sections each. m Quantification of apoptotic genes expression in heads of E10.5 embryos infected in a. n = 12 for MOCK, n = 11 for ZIKV. UD – undetectable. Data are presented as mean ± standard deviation. P values were calculated by unpaired two-tailed Student’s t-test. *P < 0.05, **P < 0.01, and ***P < 0.001. Related to Supplementary Fig. 3. Source data for 4b, d, f–h, j, m, n are provided as a Source Data file