Figure 2. Molecular characteristics and expression localization of circSOX9. (A) RNase R digestion assay was used to detect the stability of circSOX9 in HONE1 cells. (B) The qRT-PCR analysis of circSOX9 and linear SOX9 was performed by RNase R digestion assay in HONE1 cells. (C) The location of circSOX9 was detected using nucleoplasmic separation analysis in HONE1 cells. (D) The stability of circSOX9 was evaluated by RNase R digestion assay in CNE2 cells. (E) qRT-PCR analysis for circSOX9 was and linear SOX9 by RNase R digestion assay in CNE2 cells. (F) The location of circSOX9 was detected using nucleoplasmic separation analysis in CNE2 cells. (G) qRT-PCR analysis for circSOX9 and linear Sox9 in cDNA and gDNA in HONE1 and CNE2 cells. (H) Sanger sequence analysis of the back splice sequence of circSOX9. (I) RNA FISH analysis showed that circSOX9 was mainly distributed in the cytoplasm, scale bar = 50 μm. **P < 0.01, ***P < 0.001.