Fast, automated measurement of nematode swimming (thrashing) without morphometry.
Fast, automated measurement of nematode swimming (thrashing) without morphometry.
复制标题
DOI：
10.1186/1471-2202-10-84
复制
发表时间：
2009-07-20
期刊：
影响因子：
2.4
通讯作者：
Sattelle DB
中科院分区：
文献类型：
--
作者：
Buckingham SD;Sattelle DB
将线虫置于液体中并估计横向游动（“甩动”）运动的频率的“甩动测定”是测量遗传模型生物秀丽隐杆线虫以及寄生线虫运动性的行之有效的方法。它被用作药物、化学品或突变对运动影响的指标，并已被证明可用于识别影响行为的突变体。然而，该方法很费力，容易出现实验者错误，因此不允许高通量应用。现有的自动化方法通常涉及对蠕虫形状的分析，但这对计算要求很高并且容易出错。在这里，我们提出了一种新颖、稳健且快速的方法来自动计算蠕虫的抖动频率，该方法避免了形态测量，但仍然提供了抖动频率的直接测量。我们的方法使用主成分分析来去除背景，然后计算剩余图像帧的协方差矩阵，从中估计统计上相似的帧之间的间隔。我们测试了协方差方法在使用影响运动性的突变来测量蠕虫的拍打率方面的性能，发现它可以准确地替代在各种拍打率下的费力的手动测量。使用的算法还使我们能够确定驱虫药左旋咪唑对鞭打频率的剂量依赖性抑制，说明该系统适用于分析药物和化学物质对运动的影响。此外，该算法成功测量了左旋咪唑对寄生线虫捻转血矛线虫的作用，该线虫在游泳时会经历复杂的扭曲形状，而无需更改代码或任何参数，这表明该算法适用于包括寄生线虫在内的不同线虫物种。我们的方法能够在不到 30 秒的时间内分析一部 30 秒的电影，因此可以部署在快速放映中。我们证明，基于协方差的方法可以快速、可靠、自动地测量线虫的运动性，从而取代更耗时的手动方法。由于没有形态测量步骤，意味着该方法可以应用于任何在液体中游泳的线虫，而且其速度快，这种简单性适合在大规模化学和遗传筛选中部署。
The "thrashing assay", in which nematodes are placed in liquid and the frequency of lateral swimming ("thrashing") movements estimated, is a well-established method for measuring motility in the genetic model organism Caenorhabditis elegans as well as in parasitic nematodes. It is used as an index of the effects of drugs, chemicals or mutations on motility and has proved useful in identifying mutants affecting behaviour. However, the method is laborious, subject to experimenter error, and therefore does not permit high-throughput applications. Existing automation methods usually involve analysis of worm shape, but this is computationally demanding and error-prone. Here we present a novel, robust and rapid method of automatically counting the thrashing frequency of worms that avoids morphometry but nonetheless gives a direct measure of thrashing frequency. Our method uses principal components analysis to remove the background, followed by computation of a covariance matrix of the remaining image frames from which the interval between statistically-similar frames is estimated. We tested the performance of our covariance method in measuring thrashing rates of worms using mutations that affect motility and found that it accurately substituted for laborious, manual measurements over a wide range of thrashing rates. The algorithm used also enabled us to determine a dose-dependent inhibition of thrashing frequency by the anthelmintic drug, levamisole, illustrating the suitability of the system for assaying the effects of drugs and chemicals on motility. Furthermore, the algorithm successfully measured the actions of levamisole on a parasitic nematode, Haemonchus contortus, which undergoes complex contorted shapes whilst swimming, without alterations in the code or of any parameters, indicating that it is applicable to different nematode species, including parasitic nematodes. Our method is capable of analyzing a 30 s movie in less than 30 s and can therefore be deployed in rapid screens. We demonstrate that a covariance-based method yields a fast, reliable, automated measurement of C. elegans motility which can replace the far more time-consuming, manual method. The absence of a morphometry step means that the method can be applied to any nematode that swims in liquid and, together with its speed, this simplicity lends itself to deployment in large-scale chemical and genetic screens.
登录
查看更多内容
影响因子：
3
作者：
Feng Z;Cronin CJ;Wittig JH Jr;Sternberg PW;Schafer WR
通讯作者：
Schafer WR
影响因子：
--
作者：
Buckingham, Steven D.;Sattelle, David B.
通讯作者：
Sattelle, David B.
影响因子：
4.6
作者：
Tsechpenakis, Gabriel;Bianchi, Laura;Driscoll, Monica
通讯作者：
Driscoll, Monica
影响因子：
12.3
作者：
通讯作者：
--
影响因子：
2.9
作者：
Cronin CJ;Mendel JE;Mukhtar S;Kim YM;Stirbl RC;Bruck J;Sternberg PW
通讯作者：
Sternberg PW