Fig 1: Histone acetylation patterns in human placenta and primary cytotrophoblasts.a Localization of AcH2BK5, AcH3K9, AcH3K27, AcH3K14, and AcH3K18 in 6-week and 39-week human placenta. In all panels, cytotrophoblasts were detected by immunostaining for E-cadherin (red), and nuclei were counterstained using DAPI (blue). Arrowheads denote the syncytiotrophoblast layer. b Primary cytotrophoblasts were isolated from term human placenta, and cultured for 24, 48, and 72 h. At the 24-h timepoint, KRT7 (red) was detected by immunofluorescence to validate that these cells were trophoblasts. Nuclei were counterstained using DAPI (blue). CGB production was determined in conditioned media by enzyme immunoassay. c Levels of AcH2BK5, AcH3K9, AcH3K27, AcH3K14, AcH3K18, AcH3, and total histone H3 (loading control) were determined by western blotting (n = 4). Densitometric analysis relative to total histone H3 is shown beside the representative western blots. The dotted line represents signal intensity in undifferentiated cells. Graphs represent means ± SEM. Data significantly different from undifferentiated cells are indicated by an asterisk (*P < 0.05; n = 4 from different placentas). Scale bars represent 40 μm.