MicroRNA regulation of biological mechanisms

描述(申请人提供)：我们最近对一类称为microRNAs的非编码小RNA的机制和生物学有了很大的了解。这类引人注目的RNA构成了人类基因组中1%的基因，它们抑制了蛋白质编码基因的表达。在动物物种中，这主要是通过注意从含有3‘非翻译区互补序列的信息中合成蛋白质来实现的。虽然很难估计microRNA的调控程度，但4%-20%的蛋白质编码基因可能直接受microRNAs控制。对模型生物的遗传学研究支持这样的观点，即microRNAs在细胞和生物生物学中扮演着特定的角色。我们有兴趣了解microRNAs是如何具体抑制其目标基因的，以及这一调控的生物学后果。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microRNAs的方法。我们将评估78个已知果蝇microRNAs在眼睛发育过程中的表达模式。将评估调节眼睛中microRNA表达的上游调控通路，并将其与这些通路的已知生物学功能相关联。我们将使用microRNA基因突变来确定microRNAs是否参与了这些生物过程。计算机遗传学和分子遗传学相结合的方法将被用来识别和表征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(S)。我们的目标是破译microRNA在体内不同组织中关于靶标和生物特异性的调节规则。MicroRNAs的综合作用可能会影响许多人类基因的表达，而microRNAs的错误调控很可能是癌症易感性和进展等复杂疾病现象的基础。

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.