Figure 1.

ZIKV infects IPCs and post-mitotic committed neurons. (a) Human fetal brain tissues from donors at the indicated gestation ages were infected with 1 × 10⁶ plaque-forming unit (PFU) ZIKV strain MR766. Two days later, tissues were fixed, permeabilized, labeled with an anti-flavivirus E antibody and 4′,6-diamidino-2-phenylindole (DAPI). Labeled cells were imaged by fluorescent microscopy. (b) Experiments were similar to those in (a) except that infected tissues were labeled with the indicated antibodies and imaged by confocal microcopy. (c) Experiments were similar to those in (b) except that x-y, y-z, and x-z axis images are show. Arrowheads indicate ZIKV-infected Tbr2-positive cells. (d) Quantitative analysis of percentages of Tbr2-positive cells among ZIKV-infected cells in fetal brain tissues at the indicated ages. (e) Experiments were similar to those in (a,b) except that the indicated antibodies were used. (f) Experiments were similar to those in (e) except that x-y, y-z, and x-z axis images are show. Arrows indicate ZIKV-infected MAP2-positive cells. (g) Quantitative analysis of the percentage of MAP2-positive cells among ZIKV-infected cells in fetal brain tissues at the indicated ages. (d,g) More than 100 infected cells were examined for each counting. The procedures were repeated for 3 times for each sample at the indicated ages. 10–20 fields for each brain slice have been inspected to draw our conclusions. Error bars denote one s.d. (n = 3).