MicroRNA regulation of biological mechanisms

描述（由申请人提供）：我们最近已经了解了大量关于一类称为microRNA的小的非编码RNA的机制和生物学。这类RNA占人类基因组中基因的1%，它们抑制蛋白质编码基因的表达。这在动物物种中主要是通过从在其3'非翻译区中含有互补序列的信息中减少蛋白质合成来实现的。虽然很难估计microRNA调控的程度，但4 - 20%的蛋白质编码基因可能直接受microRNA控制。模式生物的遗传学研究支持microRNA在细胞和生物体生物学中发挥选择作用的观点。我们有兴趣了解microRNA如何特异性抑制其靶基因以及这种调节的生物学后果。为此，我们开发了一种通过原位杂交检测整个果蝇组织和胚胎中单个microRNA的方法。我们将评估78种已知果蝇microRNA在眼睛发育过程中的表达模式。将评估调节眼睛中microRNA表达的上游调节途径，并将其与这些途径的已知生物学功能相关联。我们将使用microRNA基因突变来确定microRNA是否参与这些生物学过程。将使用计算机模拟和分子遗传学方法的组合来鉴定和表征microRNA抑制的直接靶标，并研究控制microRNA介导的翻译抑制的特异性的机制。我们的目标是破译microRNA调节的规则，在身体的不同组织中的目标和生物特异性。microRNA的联合作用可能会影响许多人类基因的表达，而microRNA的失调可能是复杂疾病现象的基础，如癌症易感性和进展。

DESCRIPTION (provided by applicant): We have learned a great deal recently about the mechanism and biology of a class of small non-coding RNAs called microRNAs. This remarkable class of RNAs constitute 1 % of the genes in the human genome, and they repress the expression of protein-coding genes. This is achieved in animal specieis primarily by attenation of protein synthesis from messages which contain complementary sequence in their 3' untranslated regions. Although it is difficult to estimate the extent of microRNA regulation, from 4 - 20% of protein-coding genes might be directly controlled by microRNAs. Genetic studies in model organisms support the notion that microRNAs play select roles in cell and organismal biology. We are interested in understanding how microRNAs specifically inhibit their target genes and the biological consequences of this regulation. To this end, we developed a method to detect individual microRNAs in whole Drosophila tissues and embryos by in situ hybridization. We will evaluate the expression patterns of the 78 known Drosophila microRNAs during eye development. The upstream regulatory pathways that regulate microRNA expression in the eye will be evaluated, and correlated to known biological functions of these pathways. We will use microRNA gene mutagenesis to determine if microRNAs are involved in these biological processes. A combination of in silico and molecular genetic approaches will be used to identify and characterize direct targets of microRNA repression, and to investigate the mechanism(s) governing the specificity of microRNA- mediated translational repression. Our goal is to decipher the rules of microRNA regulation regarding target and biological specificity in diverse tissues of the body. The combined effects of microRNAs may affect the expression of many human genes, and misregulation of microRNAs may well underlie complex disease phenomena such as cancer susceptibility and progression.