Minke B
Biophys Struct Mech. 1977 Apr 21;3(1):59-64. doi: 10.1007/BF00536455.
The trp is a conditional phototransduction mutant of Drosophila. Direct electrical measurements and shot noise analysis suggest that a prolonged intense light causes in the mutant a reduction in the quantum efficiency for quantum bump production that does not arise from bleaching of the visual pigment. This effect depends on the duration of the light and only weakly on its intensity. In the normal fly, an intense blue light that shifts the visual pigment from rhodopsin to metarhodopsin, induces an excitatory process manifested by a prolonged depolarizing after potential (PDA). In the mutant, the PDA has a small amplitude and bump noise is superimposed on the response. It can thus be shown that the excitatory process underlying the PDA is also present in those trp mutants where the PDA voltage response is small or absent. It is suggested that the absence of the PDA voltage response in the mutant is probably due to a defect in an intermediate process, which links the excitatory process to the membrane conductance change.
trp是果蝇的一种条件性光转导突变体。直接电测量和散粒噪声分析表明，长时间的强光会导致突变体中量子隆起产生的量子效率降低，这并非源于视觉色素的漂白。这种效应取决于光照的持续时间，而对其强度的依赖较弱。在正常果蝇中，强烈的蓝光会使视觉色素从视紫红质转变为变视紫红质，诱导出一个由延长的去极化后电位（PDA）表现出的兴奋过程。在突变体中，PDA的幅度较小，并且在反应上叠加有隆起噪声。因此可以表明，PDA背后的兴奋过程在那些PDA电压反应较小或不存在的trp突变体中也存在。有人提出，突变体中PDA电压反应的缺失可能是由于一个中间过程存在缺陷，该过程将兴奋过程与膜电导变化联系起来。
