Fig. 7: LTR8B elements function as enhancers in trophoblast cells.
a, Genome browser screenshot showing the transcriptional and epigenetic states of the PSG8 gene in primary STs. The displayed datasets were obtained from the International Human Epigenome Consortium data repository41,42. The intronic ERV1 element is shaded in grey and the LTR8B elements within PSG8 are shaded in blue. All tracks are displayed as RPM, with y axes ranging from 0 to 200 for RNA-seq, 0 to 100 for H3K27ac ChIP–seq, 0 to 150 for H3K4me1 ChIP–seq, 0 to 250 for H3K4me3 ChIP–seq, 0 to 20 for H3K9me3 ChIP–seq, 0 to 40 for H3K27me3 ChIP–seq and 0 to 1 for whole-genome bisulphite sequencing (WGBS). b, Luciferase assay enhancer activity of individual intronic LTR8B elements within different PSG genes normalized to the background control. Each dot represents an independent experiment (n = 3) and data are presented as mean values with error bars showing the s.d. c, Peak-to-gene linkage analysis indicating a potential interaction between the PSG1 promoter and its intronic LTR8B (highlighted by the red box). Tracks are displayed as normalized pseudo-bulk coverage signals of each cell type from the snATAC-seq ranging from 0 to 0.25. Ctrl, control and Cov, COVID-19; cell-type abbreviations as per Fig. 1b.
