Role of the microRNA miR144 in haemopoiesis in vivo

最近发现了一种新的基因调控形式，涉及称为microRNAs（miRNAs）的小RNA分子。尽管脊椎动物（如人、小鼠和鱼）含有数百种miRNA，但每个miRNA的功能和真正的基因靶点在很大程度上是未知的。需要更好地了解miRNAs的正常功能和靶点，以便了解它们在正常生物学和疾病发展中的作用。这些研究利用斑马鱼的技术优势，在生物医学研究中越来越重要的模型，研究特定miRNA，miR 144的功能，并确定其生理靶基因。斑马鱼在研究miRNA功能方面有几个优势-几种简单的实验性改变miRNA水平的方法在斑马鱼中是标准的，但在其他模型如小鼠中并不容易。选择miR 144是因为它具有强烈提示在血液发育中的作用的表达模式。血液开发和斑马鱼技术是Lieschke实验室的中心主题。斑马鱼的初步实验表明，miR 144的表达可以在血细胞中检测到，当过表达时，它具有功能活性，其作用可以被拦截，并且其错误表达会对血液系统产生影响，特别是在血液发育异常的突变斑马鱼中，这为此类研究提供了敏感的背景。这些研究将详细描述miR 144在正常和异常斑马鱼血液发育中的表达。将详细研究miR 144过表达和表达敲低的影响。为了鉴定mir 144的靶标，将进行多方面的微阵列分析，然后将系统地测试由此提出的候选靶标的有效性。完成后，这些研究将描述这种新血液调节剂的生理学特征，并确定其发挥作用的方式。

Recently a new form of gene regulation has been discovered involving small RNA molecules called microRNAs (miRNAs). Although vertebrates (like man, mouse and fish) contain many hundreds of miRNAs, the function and true gene targets of each individual miRNA are largely unknown. A better understanding the normal function and targets of miRNAs is needed so that their role in normal biology and disease development can be understood. These studies exploit the technical strengths of zebrafish, an model of increasing importance in biomedical research, to study the function of a particular miRNA, miR144, and to identify its physiological target genes. Zebrafish have several advantages for studying miRNA function - several simple methods for experimentally altering miRNA levels are standard in zebrafish but not easy in other models like mice. miR144 has been chosen because it has an expression pattern that strongly suggests a role in blood development. Blood development and zebrafish technologies are central themes of the Lieschke laboratory. Preliminary experiments in zebrafish have shown that miR144 expression can be detected in blood cells, that it is functionally active when overexpressed, that its effect can be intercepted, and that there are blood-system effects of its misexpression, particularly in mutant zebrafish with abnormalities of blood development that provide a sensitized background for such studies. These studies will describe the expression of miR144 in detail in normal and abnormal zebrafish blood development. The effects of miR144 overexpression and knock-down of expression will be studied in detail. To identify the targets of mir144, a multifaceted microarray analysis will be performed, and the validity of candidate targets suggested by this will then be systematically tested. When finished, these studies will have characterised the physiology of this new blood regulator and identified the way it exerts its effect.