Coupling neuroimaging with CLARITY and single cell genomics to dissect sex differences in the developing brain

摘要 许多神经行为疾病对女性和男性的影响不同，并且在不同的时间出现。 生命的各个阶段，得出的结论是，一种性别是保护免受疾病的内在性别因素， 如性腺激素和性染色体。这些作用对大脑的部位和时间 发展未知。高通量高精度全脑MRI成像的方法， 在动物模型和人类中以极高的灵敏度检测这种变化的能力。这 该项目将利用这些强大的方法来分离性腺激素和性染色体的影响 在9个不同发育年龄的小鼠模型“性染色体三体”（SCT）中， 这些因素在何时何地导致了大脑发育的性别差异（目标1）。SCT模型 比较了不同数量和类型的性染色体（XX，XY，XXY，XYY）的小鼠，每种基因型 存在于雄性或雌性的性腺中。然后，一个新的分析管道将比较小鼠和人类 大脑发育的许多阶段和信息组（不同的年龄，性别，激素状态， 性染色体补体），以确定小鼠大脑中的哪些变化也存在于人类中， 与不同疾病相关的特定脑区（目的2）。分析将指出小鼠的变化 模拟人类大脑发育的大脑。这些研究还将指出新的性别偏见的影响， 激素和性染色体在小鼠特定发育阶段的局部脑区域， 从而进一步研究这些部位因性别引起的细胞和分子变化（目标3）。 将研究性别偏置因素的细胞效应（细胞大小、数量、确定的细胞群密度） 使用透明脂质交换丙烯酰胺杂交的刚性成像相容组织（Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue- 水凝胶）。个体细胞类型中响应激素和性染色体效应的基因通路 将使用单细胞RNA-seq来测量特定脑区域中的细胞数量。这些研究，结合高- 分辨率神经影像学，可重复性，和单细胞测序，将提供一个概念的基础 在大脑的哪个部位，以及在发育过程中，特定的细胞群对性做出反应， 作为假设哪些性别差异是性别保护作用的基础的前奏， 细胞中的偏见因素。

Abstract Many neurobehavioral diseases affect females and males differently, and emerge at different stages of life, leading to the conclusion that one sex is protected from diseases by inherent sex factors, such as gonadal hormones and sex chromosomes. The sites and timing of these effects on brain development are unknown. The method of high-throughput high-precision whole-brain MRI imaging has the power to detect such changes with great sensitivity, in both animal models and humans. This project will exploit these powerful methods to separate gonadal hormonal and sex chromosome effects in the mouse model “Sex Chromosome Trisomy” (SCT), at 9 different ages of development, to discover where and when these factors cause sex differences in brain development (Aim 1). The SCT model compares mice with different numbers and types of sex chromosomes (XX, XY, XXY, XYY), each genotype present in gonadal males or females. Then, a novel pipeline of analysis will compare mouse and human brain development at many stages and in informative groups (differing by age, sex, hormonal status, and sex chromosome complement) to determine which changes in mouse brain are also found in humans, in specific brain regions related to different diseases (Aim 2). The analysis will point to changes in mouse brain that model human brain development. These studies will also pinpoint new sex-biasing effects of hormones and sex chromosomes at localized brain regions at specific developmental stages in mice, leading to further investigation of cellular and molecular changes caused by sex at those sites (Aim 3). Cellular effects (cell size, number, density of defined cell populations) of sex-biasing factors will be measured using CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging-compatible Tissue- hYdrogel). Gene pathways responding to hormonal and sex chromosome effects in individual cell types in specific brain regions will be measured using single cell RNA-seq. These studies, combining high- resolution neuroimaging, CLARITY, and single cell sequencing, will provide a foundation of concepts about where in the brain, and when during development, specific cell populations respond to sex factors, as a prelude for hypothesizing which sex differences underlie the protective effects of sex- biased factors in cells.