Fig. 1: Single-cell analysis of the AF content.
a, Top left: graphical representation of AF sampling. Bottom left: the FACS plot shows the sorting strategy utilized to collect the living cell fraction, negative for propidium iodide (PI) and positive for Hoechst. Middle: the UMAP shows the content of the AF of multiple patients obtained across the second and third trimesters of pregnancy (n = 12 biologically independent AF samples spanning 15–34 GA; 33,934 cells post-filtering examined over 11 sequencing lanes). Highlighted in orange is the epithelial cluster, as identified by the SingleR cell-labeling package using the human primary cell atlas dataset as reference. Right: the violin plots show the level of expression of the pan-epithelial specific genes EPCAM, CDH1(ECAD), KRT8, KRT10, KRT17 and KRT19 (mean ± s.d., data presented as normalized counts per million (CPM)). b, The UMAPs show the expression of a selection of epithelial markers, within the epithelial cluster identified in a. c, Representative flow cytometry analysis of EpCAM (n = 58,964 cells) and ECAD (CDH1, n = 38,389 cells) expression in live-sorted cells from the AF; gray represents unstained control (n = 34,045 cells). d, Re-calculated UMAP of the epithelial cluster identified in a, highlighting cells attributed to the three tissues through scGSEA. e, Scoring of the cells identified in d, for appropriate progenitor-associated genes. Cells with a positive score are highlighted on a re-calculated UMAP of that tissue’s cells. Scores also plotted as violin plots, identifying distinct populations of progenitor cells, threshold for positive scoring shown in red.
