Extended Data Fig. 2: Mechanical cues regulate the HERV-H via YAP/TEAD1.

a, Immunofluorescence staining of YAP localization in WT hESCs cultured on substrates with different stiffness. YAP is predominantly nuclear on stiff substrates but translocates to the cytoplasm on soft substrates. Higher-magnification insets highlight nuclear versus cytoplasmic localization. b, RT-qPCR analysis of YAP target genes CCN1 and CCN2 in hESCs cultured on soft versus stiff substrates. P = 0.029, P = 0.0046. n = 3 biologically independent experiments. c, GSEA analysis indicating that YAP signature genes are negatively enriched in soft versus stiff conditions. d, Overlap of YAP/TEAD1 co-occupied genomic loci with TE sequences. The numbers of overlapping and non-overlapping loci are indicated. e, Jaccard index analysis quantifying the overlap between YAP/TEAD1 binding peaks and TE loci. f, (Left) Heatmap displaying H3K27ac ChIP-seq signals at 305 YAP/TEAD1 co-bound LTR7 loci under stiff versus soft conditions. (Right) Box plot quantifying H3K27ac signals at these loci, showing reduced enhancer activity in soft matrices. n = 2 biologically independent experiments. g, RT-qPCR analysis of HERVH-int expression in hESCs cultured on Matrigel-coated polyacrylamide hydrogels with varying stiffness. P = 5.6e-9. n = 3 biologically independent experiments. h, RT-qPCR analysis of HERVH-int expression in hESCs cultured on Matrigel-coated CytoSoft silicon gels at stiff (64 kPa) or soft (2 kPa) substrates. P = 0.012. n = 3 biologically independent experiments. i, Cell morphology and AP staining analysis of hESCs expressing empty vector or YAP5SA under self-renewal culture conditions. j, RT-qPCR analysis of OCT4 mRNA expression in hESCs expressing empty vector control or YAP5SA under self-renewal culture conditions. P = 0.00057. n = 3 biologically independent experiments. P values were calculated by the two-tailed Student’s t-test (b, g, h, j). Data in (b, g, h, j) represent mean ± s.e.m. In box plots(f), center lines represent the median value, box limits the 25th and 75th percentiles, and whiskers denote minima and maxima (1.5× the interquartile range). Source numerical data are available in source data.