Regulation of chromatin accessibility by small non-coding RNAs

骨骼肌对一生的健康和幸福都很重要。为了更好地了解有助于维持这一重要组织的因素，我们研究了它在胚胎中的发育。众所周知，许多控制胚胎发育的基因和机制在物种之间是保守的，并且在成年生物体中发挥类似的功能。小的非编码rna（称为microrna）也是如此，它们在发育和成熟的骨骼肌中高度表达，在那里它们可以具有保护功能，例如在衰老或疾病中。为了发现microrna在健康肌肉中的全部潜力，在早期鸟类的卵细胞胚胎中进行了功能实验。这些结果表明，肌肉特异性microRNAs，即所谓的myomirs，负向调节关键转录因子和表观遗传调控因子（Pax3, Gli3, BAF60a/b）的表达。这对于在祖细胞向成肌细胞过渡期间提供发育时间的稳健性以及稳定地建立肌源性分化程序是至关重要的。该项目将进一步研究myomir在胚胎肌发生中染色质可及性的作用，从而调控基因表达。使用已建立的实验操作，然后使用下一代测序进行全基因组分析，染色质可及性和鉴定新的顺式调控元件（CRE）将被表征。这些将在体内使用延时成像和crispr编辑进行验证，并将测试它们在早期肌肉发育中的作用。

Skeletal muscle is important for health and well-being throughout life. To understand better the factors that contribute to the maintenance of this important tissue, we study its development in the embryo. It is known that many of the genes and mechanisms that control embryo development are conserved across species and perform similar functions in adult organisms. This is also the case for small non-coding RNAs, called microRNAs, which are highly expressed in developing and mature skeletal muscles, where they can have a protective function, for example in ageing or disease. To discover the full potential of microRNAs for healthy muscles functional experiments are being used in early avian embryos in ovo. These showed that muscle specific microRNAs, so-called myomirs, negatively regulate the expression of crucial transcription factors and epigenetic regulators (Pax3, Gli3, BAF60a/b). This is essential to provide robustness to developmental timing during the progenitor to myoblast transition, and to stably establish the myogenic differentiation programme. The project will investigate further the role of myomirs for chromatin accessibility and thus the regulation of gene expression in embryo myogenesis. Using established experimental manipulations followed by genome-wide analysis using next generation sequencing, chromatin accessibility and identify novel cis-regulatory elements (CRE) will be characterised. These will be validated in vivo using time-lapse imaging and CRISPR-editing and their role in early muscle development will be tested.