Carrillo M A, Hallem E A
Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Mol Neurobiol. 2015;51(3):919-31. doi: 10.1007/s12035-014-8748-z. Epub 2014 Jun 8.
Nearly all animals are capable of sensing changes in environmental oxygen (O2) and carbon dioxide (CO2) levels, which can signal the presence of food, pathogens, conspecifics, predators, or hosts. The free-living nematode Caenorhabditis elegans is a powerful model system for the study of gas sensing. C. elegans detects changes in O2 and CO2 levels and integrates information about ambient gas levels with other internal and external cues to generate context-appropriate behavioral responses. Due to its small nervous system and amenability to genetic and genomic analyses, the functional properties of its gas-sensing microcircuits can be dissected with single-cell resolution, and signaling molecules and natural genetic variations that modulate gas responses can be identified. Here, we discuss the neural basis of gas sensing in C. elegans, and highlight changes in gas-evoked behaviors in the context of other sensory cues and natural genetic variations. We also discuss gas sensing in other free-living nematodes and parasitic nematodes, focusing on how gas-sensing behavior has evolved to mediate species-specific behavioral requirements.
几乎所有动物都能够感知环境中氧气（O₂）和二氧化碳（CO₂）水平的变化，这些变化可以表明食物、病原体、同种生物、捕食者或宿主的存在。自由生活的线虫秀丽隐杆线虫是研究气体感知的强大模型系统。秀丽隐杆线虫能检测O₂和CO₂水平的变化，并将有关环境气体水平的信息与其他内部和外部线索整合起来，以产生适合情境的行为反应。由于其神经系统较小，且易于进行遗传和基因组分析，其气体感知微电路的功能特性可以以单细胞分辨率进行剖析，并且可以识别调节气体反应的信号分子和自然遗传变异。在这里，我们讨论秀丽隐杆线虫气体感知的神经基础，并强调在其他感官线索和自然遗传变异的背景下气体诱发行为的变化。我们还讨论了其他自由生活线虫和寄生线虫中的气体感知，重点关注气体感知行为是如何进化以介导物种特异性行为需求的。
