The Synchrony Framework proposes that early‑specification (e.g., OTX2) and late‑differentiation (e.g., CRX) genes follow a linear, coordinated expression pattern during differentiation. We analysed two independent human retinal organoid datasets: GSE235582 (8 time points, days 10–210; single‑cell data, n = 19,006 cells) and GSE192665 (paired samples from 15 patients at day 0 and day 7). Time‑adjusted regression, partial correlation, bootstrap, leave‑one‑out sensitivity, cross‑validation, and paired t‑tests were used. In GSE235582, after controlling for developmental time, OTX2 significantly predicted CRX (partial r = 0.793, p = 0.033; 99.1% of bootstrap replicates positive). The model explained 93% of variance (R² = 0.93). Single‑cell correlation was positive (r = 0.322, p < 0.001). In GSE192665, both OTX2 and CRX increased significantly from day 0 to day 7 (paired t‑test, p < 0.001 for both). Limitations include a moderate sample size in the time‑series (8 time points), modest single‑cell correlation, and only one gene pair tested. We conclude that the Synchrony Framework receives strong empirical support from two independent datasets. OTX2 and CRX exhibit a coordinated, time‑independent linear relationship that is detectable at both population and single‑cell levels. These findings establish a quantitative principle for retinal differentiation and justify broader validation.
Saadat Samadi Dinani (Tue,) studied this question.