Palit A, Pratap P R, Lipson E D
Department of Physics, Syracuse University, New York 13244-1130.
Biophys J. 1989 Mar;55(3):519-26. doi: 10.1016/S0006-3495(89)82845-0.
The light-growth response of Phycomyces has been studied further with the sum-of-sinusoids method in the framework of the Wiener theory of nonlinear system identification. The response was treated as a black box with the logarithm of light intensity as the input and elongation rate as the output. The nonlinear input-output relation of the light-growth response can be represented mathematically by a set of weighting functions called kernels, which appear in the Wiener intergral series. The linear (first-order) kernels of wild type, and of single and double mutants affected in genes madA to madG were determined previously with Gaussian white noise test stimuli, and were used to investigate the interactions among the products of these genes (R.C. Poe, P. Pratap, and E.D. Lipson. 1986. Biol. Cybern. 55:105.). We have used the more precise sum-of-sinusoids method to extend the interaction studies, including both the first- and second-order kernels. Specifically, we have investigated interactions of the madH ("hypertropic") gene product with the madC ("night blind") and madG ("stiff") gene products. Experiments were performed on the Phycomyces tracking machine. The log-mean intensity of the stimulus was 6 x 10(-2) W m-2 and the wavelength was 477 nm. The first- and second-order kernels were analyzed in terms of nonlinear kinetic models. The madH gene product was found to interact with those of madC and madG. This result extends previous findings that themadH gene product is associated with the input and the ouput of the sensory transduction complex for the lightgrowth response.
在非线性系统识别的维纳理论框架下，采用正弦波叠加法对毛霉的光生长反应进行了进一步研究。将该反应视为一个黑箱，以光强的对数作为输入，伸长率作为输出。光生长反应的非线性输入-输出关系可以用一组称为核的加权函数进行数学表示，这些核出现在维纳积分级数中。先前使用高斯白噪声测试刺激确定了野生型以及在madA至madG基因中受影响的单突变体和双突变体的线性（一阶）核，并用于研究这些基因产物之间的相互作用（R.C. 坡、P. 普拉塔普和E.D. 利普森。1986年。生物控制论。55:105）。我们使用了更精确的正弦波叠加法来扩展相互作用研究，包括一阶和二阶核。具体而言，我们研究了madH（“过度生长”）基因产物与madC（“夜盲”）和madG（“僵硬”）基因产物之间的相互作用。在毛霉跟踪机器上进行了实验。刺激的对数平均强度为6×10⁻² W m⁻²，波长为477 nm。根据非线性动力学模型对一阶和二阶核进行了分析。发现madH基因产物与madC和madG的基因产物相互作用。这一结果扩展了先前的发现，即madH基因产物与光生长反应的感觉转导复合体的输入和输出相关。
