C. elegans Demonstrates Distinct Behaviors within a Fixed and Uniform Electric Field.
C. elegans Demonstrates Distinct Behaviors within a Fixed and Uniform Electric Field.
复制标题
DOI：
10.1371/journal.pone.0151320
复制
发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Carnell L
中科院分区：
文献类型：
--
作者：
Chrisman SD;Waite CB;Scoville AG;Carnell L
秀丽隐杆线虫会沿着不间断的笔直路径直接朝向直流电场的负极定向和行进。我们试图了解蠕虫在方向和大小都固定的均匀电场中导航到负极的策略。我们通过量化响应不同应用场强的趋电行为的三个方面来检查这种行为：动物轨迹的平均接近轨迹角度、转弯行为（旋转）和平均种群速度。我们确定线虫会在次首选场强下直接对准电场的负极，并在较高场强下改变接近轨迹，以将滑行保持在我们计算出的首选范围内，约为 5V/cm。我们试图找出负责动物追踪首选场强的感觉神经元。两栖类感觉神经元的谷氨酸信号传导缺陷的 eat-4 突变动物具有严重的趋电性缺陷，而 ceh-36 突变动物在两种类型的感觉神经元 AWC 和 ASE 的终末分化方面存在缺陷，因此具有部分趋电性缺陷。为了进一步阐明 AWC 神经元的作用，我们检查了每对 AWC 神经元（AWCOFF 和 AWCON）的作用，它们在功能上不对称并表达不同的基因。 nsy-5/inx-19 突变体动物（将两个神经元表达为 AWCOFF）的趋电行为严重受损，而 NSY-1 突变体（将两个神经元表达为 AWCON）能够区分导航到电场内特定场强所需的场强。我们还测试了对 AWC 神经元进行靶向基因消融的菌株，发现这些动物仅表现出方向性和转向行为的轻微破坏。这些结果表明，AWC 神经元在均匀固定场内的趋电行为中，功能完全丧失比功能不对称丧失的破坏性更小。
C. elegans will orient and travel in a straight uninterrupted path directly towards the negative pole of a DC electric field. We have sought to understand the strategy worms use to navigate to the negative pole in a uniform electric field that is fixed in both direction and magnitude. We examined this behavior by quantifying three aspects of electrotaxis behavior in response to different applied field strengths: the mean approach trajectory angles of the animals’ tracks, turning behavior (pirouettes) and average population speeds. We determined that C. elegans align directly to the negative pole of an electric field at sub-preferred field strength and alter approach trajectories at higher field strengths to maintain taxis within a preferred range we have calculated to be ~ 5V/cm. We sought to identify the sensory neurons responsible for the animals’ tracking to a preferred field strength. eat-4 mutant animals defective in glutamatergic signaling of the amphid sensory neurons are severely electrotaxis defective and ceh-36 mutant animals, which are defective in the terminal differentiation of two types of sensory neurons, AWC and ASE, are partially defective in electrotaxis. To further elucidate the role of the AWC neurons, we examined the role of each of the pair of AWC neurons (AWCOFF and AWCON), which are functionally asymmetric and express different genes. nsy-5/inx-19 mutant animals, which express both neurons as AWCOFF, are severely impaired in electrotaxis behavior while nsy-1 mutants, which express both neurons as AWCON, are able to differentiate field strengths required for navigation to a specific field strength within an electric field. We also tested a strain with targeted genetic ablation of AWC neurons and found that these animals showed only slight disruption of directionality and turning behavior. These results suggest a role for AWC neurons in which complete loss of function is less disruptive than loss of functional asymmetry in electrotaxis behavior within a uniform fixed field.