Molecular cause of the differential activity of Sox8 and Sox10 in oligodendroglial cells

Oligodendroglial cells are responsible for the generation of myelin sheaths in the central nervous system and thereby render rapid saltatory conduction possible. During development, oligodendroglial cells express the three paralogous transcription factors Sox8, Sox9 and Sox10. In mature oligodendrocytes Sox8 and Sox10 expression persists. Whereas Sox9 and Sox10 fulfill important regulatory roles in these cells, Sox8 has only a limited impact on oligodendroglial development and myelination. By replacing Sox10 with Sox8 or Sox9 in the oligodendroglial Oln93 cell line and by comparing expression profiles, we show that Sox8 regulates the same processes as Sox10 and Sox9, but has a substantially lower transcriptional activity under standard culture conditions.少突胶质细胞（Oligodendroglial cells）负责中枢神经系统（central nervous system）内髓鞘（myelin sheaths）的生成，由此为快速跳跃式传导（saltatory conduction）提供了基础。在个体发育过程中，少突胶质细胞会表达三种旁系同源转录因子（paralogous transcription factors）Sox8、Sox9与Sox10。在成熟少突胶质细胞中，Sox8与Sox10的表达仍会持续维持。尽管Sox9与Sox10在这类细胞中发挥着关键的调控作用，但Sox8仅对少突胶质细胞的发育与髓鞘形成（myelination）具有有限的影响。本研究通过在少突胶质细胞系Oln93（Oligodendroglial Oln93 cell line）中以Sox8或Sox9替换Sox10，并对比分析二者的表达谱（expression profiles），证实Sox8可调控与Sox10、Sox9完全一致的生物学过程，但在标准培养条件（standard culture conditions）下，其转录活性（transcriptional activity）显著更低。