Figure 3. RNA-seq data analysis. (A) PCA was conducted on samples from four groups (CK1, CK2, OA1 and OA2). (B) A volcano plot of 327 DEGs, including 67 downregulated genes and 260 upregulated genes in response to OA treatment was drawn. (C) Each DEG was labeled on 23 pairs of chromosomes of the human genome based on the genome location information. (D) The Euclidean method was used to calculate the distance and combined with the longest distance method (complete linkage) to conduct two-way hierarchical clustering analysis on the 327 DEGs and the samples of four groups.