Regulation of chromatin accessibility by small non-coding RNAs

骨骼肌对一生的健康和福祉都很重要。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不同物种之间是保守的，并在成年生物体中发挥类似的功能。小的非编码RNA，称为microRNAs也是如此，它们在发育和成熟的骨骼肌中高度表达，在那里它们可以起到保护作用，例如在衰老或疾病中。为了发现microRNAs对健康肌肉的全部潜力，功能实验正在用于早期禽类胚胎的卵子中。这表明，肌肉特异的microRNAs，即所谓的myomiRs，负向调节关键转录因子和表观遗传调节因子(Pax3，Gli3，BAF60a/b)的表达。这对于在祖细胞向成肌细胞的转变过程中提供对发育时机的稳健性，以及稳定地建立成肌细胞分化计划是至关重要的。该项目将进一步研究myomiRs在染色质可及性中的作用，从而调节胚胎肌肉发生中的基因表达。利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，染色质的可及性和识别新的顺式调节元件(Cre)将具有特征。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.