Single-Cell Approaches to Reveal How Jumping Genes Individualize Neural Circuits

描述（由申请人提供）：与个体中大多数健康细胞具有相同基因组的传统观点相反，现在已知内源性L1反转录转座子在神经发生期间“跳跃”并改变神经元基因组。独特基因组的多样性和普遍性是未知的，但这些是了解移动的元素介导的遗传多样性如何影响神经回路的基本数据。群体中的遗传多样性不能使用典型的批量分析一百万左右的细胞来测量，因此，我们建议开发单细胞方法来分析单个神经元基因组中的反转录转座。为了了解从头移动的元件插入的多样性和普遍性（即马赛克组成）如何改变神经元功能，我们提出了三个实验。在一个实验中，我们将研究行为异常值中特定神经回路的马赛克组成。第二个实验将测试新的移动的元件插入差异地改变单个神经元的转录组的期望。在第三个实验中，我们将产生具有很少或没有反转录转座的小鼠系，以确定移动的元件插入对于神经元功能的特定方面是否是必要的和足够的。总之，应用单细胞基因组学方法来了解神经元的多样性有望挑战有关行为遗传学和人类神经发育障碍起源的基本假设。

DESCRIPTION (provided by applicant): Contrary to the conventional wisdom that the majority of healthy cells in an individual have identical genomes, endogenous L1 retrotransposons are now known to 'jump' during neurogenesis and change neuronal genomes. The diversity and prevalence of unique genomes is unknown, but these are essential data for understanding how mobile element-mediated genetic diversity affects neural circuits. Genetic diversity in a population cannot be measured using typical bulk analysis of a million or so cells; therefore, we propose to develop single cell methods to analyze retrotransposition in individual neuronal genomes. To understand how the diversity and prevalence (i.e. the mosaic composition) of de novo mobile element insertions alters neuron function, we propose three experiments. In one experiment, we will examine the mosaic composition of specific neural circuits in behavioral outliers. A second experiment will test the expectation that new mobile element insertions differentially alter the transcriptome of individual neurons. In a third experiment, we will generate mouse lines with little or no retrotransposition to determine if mobile element insertions are both necessary and sufficient for specific aspects of neuron function. Taken together, the application of single cell genomic approaches to understand neuronal diversity promises to challenge basic assumptions about the genetics of behavior and the origin of human neurodevelopmental disorders.