Cell lineage-based investigation of chemosensory neuron development

项目摘要 来自化学感觉神经元的信号调节动物生理和行为的变化 环境和社会线索。感觉神经解剖学在线虫中是如此广泛地保守，以至于基于 形态和胞体位置，功能上同源的化学感觉神经元已被鉴定 跨越广泛差异的线虫属，包括研究得很好的自由生活线虫线虫 线虫、穿透皮肤的人类寄生虫斯特氏线虫和捕食性线虫Pristionchus 和平之星。 尽管有这种同源性，但人们对发育和遗传程序的保护知之甚少 产生单独的化学感觉神经元，并维持或分化它们的功能。在多大程度上 解剖学上的同源神经元具有保守的化学感觉功能？在多大程度上 解剖同源性反映了共同的发育程序？我们将通过映射来回答这些问题 产生化学感觉神经元的细胞谱系，决定了在多大程度上 同源的化学感觉神经元是由保守的转录调节因子指定的，并识别 保守的化学感觉功能。我们将通过开发一种新的3D样式传递卷积来实现这一点 神经网络(StCNN)，用于自动识别主要细胞特征，如细胞核和细胞 具有差分干涉对比(DIC)的透射光成像中的薄膜。然后我们将使用此工具 为了重建S.stercoralis和P.pacphaus的胚胎谱系，绘制了已知的调控因子的表达图谱。 化学感觉神经对这些谱系的认同，并评估同源基因之间的功能保守性 通过执行激光细胞消融和单虫趋化试验来检测化学感受性神经元。 这项工作与人类健康直接相关，因为化学感觉调节着发育的许多方面， 和其他人类寄生线虫的生理和行为。寄生线虫侵染 并导致一些最常见和最具破坏性的被忽视的热带疾病， 尤其是在低资源环境中。我们的多物种方法将使我们能够确定哪些方面 线虫的化学感觉系统的发育和功能是广泛保守的，其中包含物种-- 驱动特定物种行为的特定适应，包括寄生行为。此外， 从DIC图像中自动重建细胞谱系将是一个具有广泛价值的使能工具。一种能力 在没有转基因的情况下绘制新的发育谱系将在研究人类胚胎发育过程中具有特别的变革性。 人类寄生线虫，如钩虫，不受基因操纵，可以 扩展到非线虫物种，包括早期脊椎动物胚胎。

Project Summary Signaling from chemosensory neurons regulates changes in animal physiology and behavior in response to environmental and social cues. Sensory neuroanatomy is so broadly conserved in nematodes that, based on morphology and cell body position, functionally homologous chemosensory neurons have been identified across widely divergent nematode genera, including the well-studied free living nematode Caenorhabditis elegans, the skin-penetrating human parasite Strongyloides stercoralis, and the predatory nematode Pristionchus pacificus. Despite this homology, little is known about the conservation of the developmental and genetic programs that produce individual chemosensory neurons and maintain or differentiate their function. To what extent do anatomically homologous neurons share conserved chemosensory function? And to what extent does anatomical homology reflect a common developmental program? We will answer these questions by mapping the cell lineages that give rise to chemosensory neurons, determining the extent to which positionally homologous chemosensory neurons are specified by conserved transcriptional regulators, and identifying conserved chemosensory function. We will achieve this by developing a novel 3D style transfer convolutional neural network (stCNN) to automate the identification of major cellular features such as the nucleus and cell membrane in transmitted light imaging with differential interference contrast (DIC). We will then use this tool to reconstruct the embryonic lineages of S. stercoralis and P. pacificus, map the expression of known regulators of chemosensory neural identity to these lineages, and assess the conservation of function between homologous chemosensory neurons by performing laser cell ablations and single-worm chemotaxis assays. This work has direct relevance to human health, since chemosensation regulates many aspects of development, physiology, and behavior in S. stercoralis and other human-parasitic nematodes. Parasitic nematodes infect over a billion people worldwide and cause some of the most common and devastating neglected tropical diseases, particularly in low-resource settings. Our multi-species approach will allow us to determine which aspects of nematode chemosensory system development and function are broadly conserved, and which contain species- specific adaptations that drive species-specific behaviors, including parasitic behaviors. Furthermore, the automated reconstruction of cell lineages from DIC images will be an enabling tool of broad value. The ability to map new developmental lineages without transgenesis will be especially transformative in the study of human-parasitic nematodes such as hookworms that are not amenable to genetic manipulation, and can be extended to non-nematode species, including early-stage vertebrate embryos.