EAGER: Developing Oxytricha Trifallax as a Model System for Small RNA Biogenesis and Function

智力优势：该项目解决了基因的组织是如何通过小RNA的作用代代相传的。它涉及对一种不寻常的单细胞池塘生物Oxytricha trifallax的遗传组织的研究，该生物含有两种保存遗传信息的细胞核。所有的基因转录和活性都发生在大核中。这个极不寻常的细胞核包含16，000个不同的基因大小的染色体，称为纳米染色体。相比之下，微核是为下一代储存遗传信息的细胞核。它有很长的染色体，每一条都有成千上万的基因。在有性交配过程中，微核在细胞之间交换（类似于动物中卵子和精子核的融合），并形成新的二倍体微核。新的微核分裂一次，它的一个子细胞发育成新的大核。大核发育的过程包括消除微核中95%的独特序列。被消除的序列不仅存在于基因之间，而且存在于注定成为单个纳米染色体的区域内。Oxytricha macronuclear发育中一个有趣的转折是，对于许多基因来说，需要连接以形成纳米染色体的片段以混乱的顺序发生。需要复杂的DNA重排来解读微核基因组，消除不需要的序列，并将剩下的序列粘贴到单个纳米染色体中。该项目探索了一种假说，即称为27macRNAs的小RNA，来自亲本大核中的序列，仅在Oxytricha交配期间产生，在指导下一代大核发育中发挥作用。从本质上讲，这个想法是亲本大核以这些小RNA的形式提供表观遗传信息，以指导下一代大核中将存在哪些序列。该项目的目标是开发Oxytricha系统作为理解小RNA如何产生以及它们如何影响DNA结构的模型。Oxytricha 27macRNA产生的一个不寻常的方面是，与动物中已知的小RNA类别不同，这些小RNA的产生是显着诱导的。了解这种诱导的细节可以为小RNA介导的调控的新方面提供变革性的见解。更广泛的影响。 该项目将支持研究生和本科生的培训，部分通过与NIH资助的UCSC少数民族获得研究职业（MARC）计划的合作，PI是该计划的负责人。这个项目是完美的介绍本科生兴奋的生物化学和生物信息学研究科学。

Intellectual Merit: This project addresses how the organization of genes is inherited from generation to generation through the action of small RNAs. It involves the study of the genetic organization of an unusual single-celled pond organism, Oxytricha trifallax, which contains two kinds of nuclei where genetic information is held. All gene transcription and activity occurs in the macronucleus. This highly unusual nucleus contains 16,000 different gene-sized chromosomes called nanochromosomes. By contrast, the micronucleus is the nucleus that stores genetic information for the next generation. It has long chromosomes each with thousands of genes. During sexual mating, micronuclei are exchanged between cells (similar to fusion of egg and sperm nuclei in animals), and a new diploid micronucleus is formed. The new micronucleus divides once, and one of its daughters develops into the new macronucleus. The process of macronuclear development involves elimination of 95% of the unique sequences in the micronucleus. Sequences that are eliminated are not only found between genes, but also within the regions destined to become individual nanochromosomes. One fascinating twist in Oxytricha macronuclear development is that for many genes, the pieces that need to be joined to form a nanochromosome occur in a scrambled order. Complex DNA rearrangements are required to unscramble the micronuclear genome, eliminate the unwanted sequences, and paste together what is left into the individual nanochromosomes. This project explores the hypothesis that small RNAs called 27macRNAs, that are derived from sequences in the parental macronucleus and are made only during mating in Oxytricha, play a role in guiding macronuclear development in the next generation. In essence the idea is that the parental macronucleus is providing epigenetic information in the form of these small RNAs to guide which sequences will be present in the macronucleus in the next generation. The goal of the project is to develop the Oxytricha system as a model for understanding how small RNAs are produced and how they affect DNA structure. One unusual aspect of Oxytricha 27macRNA production is that, unlike known small RNA classes in animals, the production of these small RNAs is dramatically induced. Understanding the details of this induction could provide transformative insights to a new aspect of small RNA-mediated regulation. Broader Impacts. The project will support training of both graduate and undergraduate students, in part through collaboration with the NIH-funded UCSC Minority Access to Research Careers (MARC) program for which the PI is director. This project is perfect for introducing undergraduates to the excitement of biochemical and bioinformatics research science.