Cell lineage-based investigation of chemosensory neuron development

项目摘要 来自化学感受神经元的信号传导调节动物生理学和行为的变化， 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， 形态和细胞体位置，功能同源的化学感受神经元已被鉴定 在广泛不同的线虫属，包括充分研究的自由生活线虫小杆线虫 线虫、穿透皮肤的人体寄生虫粪类圆线虫和捕食性线虫Pristionchus 太平洋。 尽管有这种同源性，但对发育和遗传程序的保护知之甚少， 产生单独的化学感受神经元并维持或分化它们的功能。在多大程度上 解剖学上同源的神经元共享保守的化学感受功能？在多大程度上 解剖学上的同源性反映了一个共同的发展程序？我们将通过绘制 产生化学感受神经元的细胞谱系，决定了位置上 同源的化学感受神经元由保守的转录调节因子指定，并且鉴定 保守的化学感受功能。我们将通过开发一种新的3D风格的卷积传输来实现这一目标。 神经网络（stCNN），用于自动识别主要的细胞特征，如细胞核和细胞 薄膜在透射光成像与微分干涉对比度（DIC）。我们将使用这个工具 重建S. Stercoralis和P. pacificus，绘制了已知的 化学感觉神经的身份，这些谱系，并评估同源之间的功能保守性 化学感觉神经元通过执行激光细胞消融和单蠕虫趋化性测定。 这项工作与人类健康直接相关，因为化学感觉调节发育的许多方面， 生理学和行为学的研究。粪线虫和其他人类寄生线虫。寄生线虫感染了 世界上有10亿人感染了这种疾病，并导致了一些最常见和最具破坏性的被忽视的热带疾病， 特别是在资源匮乏的环境中。我们的多物种方法将使我们能够确定 线虫化学感受系统的发育和功能是广泛保守的，其中包括物种- 特定的适应，驱动物种特异性行为，包括寄生行为。而且 从DIC图像自动重建细胞谱系将是具有广泛价值的使能工具。的能力 在没有转基因的情况下绘制新的发育谱系， 人类寄生线虫，如钩虫，不适合遗传操作，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.