Objectives: This study aimed to clarify the regulation and mechanism of meiotic initiation in FGSC development.
Materials and methods: FGSCs were induced to differentiate into meiosis in differentiation medium. RNA sequencing was performed to analysis the difference of transcription level. High-through chromosome conformation capture sequencing (Hi-C) was performed to analysis changes of three-dimensional chromatin structure. Chromosome conformation capture further confirmed a spatial chromatin loop. ChIP-qPCR and dual luciferase reporter were used to test the interaction between Stimulated by retinoic acid gene 8 (STRA8) protein and Trip13 promoter.
Results: Compared with FGSCs, the average diameter of STRA8-positive germ cells increased from 13 μm to 16.8 μm. Furthermore, there were 4788 differentially expressed genes between the two cell stages; Meiosis and chromatin structure-associated terms were significantly enriched. Additionally, Hi-C results showed that FGSCs underwent A/B compartment switching (switch rate was 29.81%), the number of topologically associating domains (TADs) increasing, the average size of TADs decreasing, and chromatin loop changes at genome region of Trip13 from undifferentiated stage to meiosis-initiation stage. Furthermore, we validated that Trip13 promoter contacted distal enhancer to form spatial chromatin loop and STRA8 could bind Trip13 promoter to promote gene expression.
Conclusion: FGSCs underwent chromatin structure remodelling from undifferentiated stage to meiosis-initiation stage, which facilitated STRA8 binding to Trip13 promoter and promoting its expression.
© 2022 The Authors. Cell Proliferation published by John Wiley & Sons Ltd.