Characterization of conserved post-transcriptional mechanisms regulating stem cells in planarians and mice

多能性描述了一种细胞产生生物体的所有细胞类型的潜力。目前主要通过iPS技术在胚胎组织培养细胞或体细胞培养细胞中进行研究。然而，这些细胞被剥夺了自然环境，并且缺乏通过细胞外分子在干细胞利基内的重要相互作用。在目前的研究中，我们的目标是识别和研究体内控制干细胞行为的保守的调控网络和机制。我们将使用两种模式生物的干细胞系统，即脊椎动物成体干细胞和小鼠雄性生殖系干细胞，它们具有发育多能性和再生力的显著特征。有了这两个实验系统，我们将能够超越常用的体外培养系统，使用原生动物和小鼠作为体内培养皿来研究多能干细胞。鉴于调控干细胞的转录后机制在很大程度上被忽视了，我们将把这些过程确立为控制多能性的关键因素。利用对先前表达数据的生物信息学分析，将识别编码具有假定的RNA结合基序的蛋白质的基因及其潜在的调控网络。利用快速高效的RNA干扰技术(RNAi)和新近建立的小鼠CRISPR/Cas9基因编辑系统，分析了脊椎动物成体干细胞和小鼠精原干细胞(SSCs)中保守的RNA调控基因的功能和相互作用伙伴。我们的研究将对控制成体干细胞自我更新和分化的转录后机制提供重要的见解，并为其在促进组织再生和治疗男性不育方面的生物医学开发提供基础。

Pluripotency describes the potential of a cell to give rise to all cell types of an organism. It has been mainly studied in cultured cells derived from embryonic tissues or from somatic cells through iPS technology. However, these cells are deprived of their natural environment and lack important interactions within a stem cell niche through extracellular molecules. In the presented study, we aim to identify and investigate conserved regulatory networks and mechanisms that control stem cell behaviour in vivo. We will use the stem cell systems of two model organisms, planarian adult stem cells and mouse male germline stem cells, which share remarkable features of developmental pluripotency and regenerative power. With the two experimental systems we will be able to go beyond commonly used in vitro culture systems and use planarians and mice as in vivo Petri dishes for research on pluripotent stem cells. Given that posttranscriptional mechanisms for regulating stem cells have been largely neglected, we will establish these processes as crucial players in the control of pluripotency. Using bioinformatics analyses of previous expression data, genes encoding proteins with putative RNA binding motifs and their potential regulatory networks will be identified. Taking advantage of fast and efficient gene silencing by RNA interference (RNAi) in planarians and the recently developed CRISPR/Cas9 gene editing system in mouse, conserved RNA regulating genes will be analyzed for their functions and interaction partners in planarian adult stem cells and mouse spermatogonial stem cells (SSCs). Our study will provide important insights into post-transcriptional mechanisms that control self-renewal versus differentiation of adult stem cells and provide bases for their biomedical exploitation for enhancing tissue regeneration and treating male infertility.