MicroRNA regulation of an insect diapause

全球气候变化的一个后果是，具有重要医学和经济意义的昆虫物种的季节分布发生了变化。随着气温的升高，许多物种在春季出现得更早，每年产生更多的世代，因此对人类的福祉产生了更大的影响。了解昆虫如何将它们的季节发育与适当的生长和发育季节相协调，对于预测关键昆虫物种的季节分布变化至关重要。一年中的大部分时间不适合持续发育，在这段时间里，许多昆虫进入休眠期，称为滞育期。滞育使昆虫能够“逃脱”可预见的恶劣环境条件时期。滞育以发育停滞和新陈代谢减慢为特征，除了保护昆虫免受极端环境的伤害外，还显著延长了昆虫S的寿命。本研究的目的是通过研究microRNAs(MiRNAs)在启动和维持肉蝇滞育过程中的调节作用，进一步了解滞育的分子基础。MiRNAs是转录后调节基因表达的小RNA片段。它们代表了一种表观遗传机制，可以在不改变潜在DNA序列的情况下改变生物体的表型(即形态或生理属性)。这些小RNA似乎是滞育所必需的，因为编码miRNA加工机制组件的基因在滞育的水泡夜蛾幼虫中比在非滞育的同龄人中更高表达。已知miRNAs调节对建立和维持滞育很重要的生物过程，包括发育时间、新陈代谢和抗逆性。这些研究还将提供有关miRNAs的母系遗传以及母体病史对miRNAs表达和活性的影响的新信息。在美洲斑潜蝇中，母体效应防止了经历滞育的雌性后代滞育。母性效应通常调节昆虫的滞育，特别是在双翅目中，但关于这种母性效应是如何由miRNAs或任何其他因素调节的知之甚少。总而言之，这项研究有望提供关于滞育调节和昆虫滞育的季节性模式的全新信息。了解miRNA是如何调控雌性果蝇母体滞育的？S的后代可能会提供新的工具来操纵滞育反应，最终控制害虫的种群暴发。除了提供关于滞育如何调节的新信息，这项研究还将为非果蝇产生一些第一个miRNA序列。我们预计，新的miRNA序列将有助于为未来研究昆虫miRNA序列的进化提供基础，并为理解这些小RNA在动物适应不断变化的环境中的生态相关性建立一个框架。这项研究将为博士后研究员、研究生和本科生提供培训。它还将使实验室成员能够继续与哥伦布地区的当地小学、高中和公共图书馆开展外联计划。

One consequence of global climate change is a shift in the seasonal distribution of medically and economically important insect species. As temperatures increase many species are emerging earlier in the spring and producing more generations per year, thus having a bigger impact on human well being. Knowing how insects coordinate their seasonal development with appropriate seasons for growth and development is critical for predicting changes in seasonal distribution of key insect species. Much of the year is unsuitable for continuous development and during this time many insects enter a period of dormancy known as diapause. Diapause allows insects to "escape" from predictable periods of harsh environmental conditions. Characterized by arrested development and reduced metabolism, diapause significantly increases an insect?s lifespan in addition to providing protection from environmental extremes. The aim of this research is to further our understanding of the molecular basis of diapause by examining the regulatory role of microRNAs (miRNAs) in initiating and maintaining diapause in the flesh fly, Sarcophaga bullata. miRNAs are small RNA fragments that post-transcriptionally regulate gene expression. They represent one type of epigenetic mechanism that can change the phenotype (i.e., morphological or physiological attributes) of an organism without changing the underlying DNA sequence. These small RNAs appear to be essential for diapause because genes that encode components of the miRNA processing machinery are more highly expressed in diapausing S. bullata pupae than in their non-diapause counterparts. miRNAs are known to regulate biological processes that are important for establishing and maintaining diapause, including developmental timing, metabolism, and stress-resistance. These studies will also provide new information about the maternal inheritance of miRNAs and the influence of maternal history on the expression and activity of miRNAs. In S. bullata a maternal effect prevents diapause in offspring of females that have gone through diapause. Maternal effects commonly regulate diapause in insects, especially in Diptera, but little is known about how such maternal effects are regulated by miRNAs or any other factor. Together, this research is expected to provide entirely new information about the regulation of diapause and the seasonal patterns of insects that are a consequence of diapause. Understanding how miRNAs regulate the maternal block of diapause in the female?s progeny may provide new tools to manipulate the diapause response and, ultimately, control population outbreaks of insect pests.In addition to providing new information about how diapause is regulated, this research will generate some of the first miRNA sequences for a non-Drosophila fly. We anticipate that the new miRNA sequences will help provide a foundation for future studies on the evolution of insect miRNA sequences and establish a framework for understanding the ecological relevance of these small RNAs in the adaptations of animals to an ever-changing environment. This research will provide training for a postdoctoral researcher, and graduate and undergraduate students. It will also enable members of the laboratory to continue their outreach programs with local elementary schools, high schools and public libraries in the Columbus area.