Correlation coefficient analysis of AS event

Dynamic transcriptional expression patterns from early to late stages of embryonic development were used as a gene or transcript characteristic to determine the correlation coefficient between homoeologous genes or homoeologous AS events. Pairwise comparisons of these gene and transcript characteristics among three members of a triad were performed through (i) Pearson's correlation coefficient (r) using TPM values of gene expression and (ii) Spearman's rank correlation coefficient (ρ) using PSI, respectively, using cor function in R base package. P‐values were calculated using the corr.test function in R psych package. Conserved correlation of gene expression patterns was defined as r > 0.8 in all three pairwise correlation analysis, while unconserved AS events were defined as ρ < 0.5 existing in at least one pairwise correlation analysis. Correlation analysis of TPM/PSI matrices was performed using the mapply function in R base package.