(A) Overview of differentiation, including early hCNCCs at day 11 (D11), passage 1–2 early hCNCCs (P1–2), P3–4 late hCNCCs, and chondrocytes at day 5 and 9.
(B) Schematic of allele-specific RT-ddPCR indicating primers and LNA probes (HEX/FAM) for T/C SNP (rs74999341) in SOX9 3’UTR. Wildtype (left), heterozygous EC1.45 deletion (right).
(C) RT-ddPCR for wildtype (green boxplot) and EC1.45 heterozygous deletion (red), plotting SOX9 C:T expression ratio.
(D) ATAC-seq reveals hCNCC-specific accessibility for EC1.45. Representative traces from 3–4 replicates.
(E) Luciferase assay for late hCNCCs (left) and chondrocytes (right). A COL2A1 enhancer is active in both cell types, while EC1.45 and EC1.25 become inactive in chondrocytes.
See also Figure S4 and Table S3.