Matsuoka Tomohiro, Gomi Sohei, Shingai Ryuzo
Laboratory of Bioscience, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.
J Theor Biol. 2008 Jan 21;250(2):230-43. doi: 10.1016/j.jtbi.2007.10.002. Epub 2007 Oct 7.
The nematode Caenorhabditis elegans has been reported to exhibit thermotaxis, a sophisticated behavioral response to temperature. However, there appears to be some inconsistency among previous reports. The results of population-level thermotaxis investigations suggest that C. elegans can navigate to the region of its cultivation temperature from nearby regions of higher or lower temperature. However, individual C. elegans nematodes appear to show only cryophilic tendencies above their cultivation temperature. A Monte-Carlo style simulation using a simple individual model of C. elegans provides insight into clarifying apparent inconsistencies among previous findings. The simulation using the thermotaxis model that includes the cryophilic tendencies, isothermal tracking and thermal adaptation was conducted. As a result of the random walk property of locomotion of C. elegans, only cryophilic tendencies above the cultivation temperature result in population-level thermophilic tendencies. Isothermal tracking, a period of active pursuit of an isotherm around regions of temperature near prior cultivation temperature, can strengthen the tendencies of these worms to gather around near-cultivation-temperature regions. A statistical index, the thermotaxis (TTX) L-skewness, was introduced and was useful in analyzing the population-level thermotaxis of model worms.
据报道，线虫秀丽隐杆线虫表现出趋温性，即对温度的一种复杂行为反应。然而，先前的报道之间似乎存在一些不一致之处。群体水平趋温性研究的结果表明，秀丽隐杆线虫能够从温度较高或较低的附近区域导航到其培养温度区域。然而，单个秀丽隐杆线虫在高于其培养温度时似乎仅表现出嗜冷倾向。使用简单的秀丽隐杆线虫个体模型进行的蒙特卡洛风格模拟有助于澄清先前研究结果中明显的不一致之处。使用包含嗜冷倾向、等温跟踪和热适应的趋温性模型进行了模拟。由于秀丽隐杆线虫运动的随机游走特性，仅高于培养温度的嗜冷倾向会导致群体水平的嗜热倾向。等温跟踪，即在先前培养温度附近的温度区域积极追踪等温线的一段时间，可以增强这些线虫聚集在接近培养温度区域的倾向。引入了一个统计指标，趋温性（TTX）L偏度，它有助于分析模型线虫的群体水平趋温性。
