FIG 2.

ZIKV infection kinetics in maternal-decidual and fetus-derived chorionic villus organ cultures. Decidual and chorionic villus cultures were infected in parallel with ZIKV or HCMV (5 × 10⁴ PFU/well). (A, B, and E) Levels of ZIKV RNA, determined by quantitative RT-PCR, at the indicated times postinfection. The levels of tissue-associated ZIKV RNA in infected tissues, normalized to β-actin, are shown in panels A and E. The copy number of extracellular ZIKV RNA measured in the supernatants of the early-gestation-infected tissues is shown in panel B. (C) Infectious ZIKV progeny titers in the supernatants of the same infected tissues at the indicated times postinfection, determined by a standard plaque assay. (D) Levels of HCMV DNA, normalized to RNase P, in tissues infected in parallel to those in panel A. (E) Levels of tissue-associated ZIKV RNA following infection of tissues obtained at midgestation. (F) Comparison of normalized tissue-associated ZIKV and HCMV genome copies following infection of tissues obtained at early gestation versus midgestation. The data shown are representative of 3 independent experiments. Each point represents the mean ± SEM from 5 biological replicates. PR, ZIKV strain PRVABC59, isolated in Puerto Rico in 2015; AFR, ZIKV strain MP1751, isolated in Uganda, Africa, in 1962.