Studies of Eye Pigments of Drosophila. I. Methods of Extraction and Quantitative Estimation of the Pigment Components.
Studies of Eye Pigments of Drosophila. I. Methods of Extraction and Quantitative Estimation of the Pigment Components.
复制标题
果蝇眼睛色素的研究。
作者：
B. Ephrussi;J. L. Herold
显微镜观察，以及对基因替换的M效应的溶解测试和研究表明，正常的野生型黑腹果蝇的眼睛颜色是由于存在两种色素，红色和棕色。这两种颜料是两个在很大程度上相互独立的反应链的最终产物。最近关于果蝇眼睛颜色的基因控制的工作几乎完全局限于导致棕色色素形成的反应链。色氨酸衍生的代表这一链中间环节的激素样可扩散物质是这一过程中研究最深入的阶段。相反，对导致红色颜料形成的反应链的研究却被忽视了，对这两个反应链的最终产物，即红色和棕色颜料本身的研究也是如此。技术和理论因素都是造成这种不均衡进步的原因。从技术上讲，荷尔蒙类物质的可扩散性质使它们特别容易受到非常直接的实验性攻击。参与红色颜料形成的中间产物没有提供这样的技术优势。据我们所知，红色色素的来源完全是细胞内和局部的。对颜料本身的研究遇到了技术障碍，主要是在寻找合适的溶剂方面，这极大地阻碍了对其化学性质的了解。直到最近，贝克尔(1939,1942)的一项最有希望的研究才在一定程度上澄清了颜料的化学性质，但这一领先地位因贝克尔在俄罗斯前线的死亡而被打破。在上述技术因素的基础上，可能还会增加两个理论方面的考虑。在所讨论的工作的早期阶段，似乎可以假定可扩散物质与控制其生产的基因之间存在相当直接的关系。人们有理由希望，从有形的可扩散物质开始，更容易追溯到基因整个中间反应链，将基因与它们控制的特征联系起来。这种可能性对某些研究人员具有特别的吸引力，而对其他人来说，可扩散物质作为发现发展中的空间和时间相关性的手段特别感兴趣。无论每一种情况的原因是什么，最终的结果是导致棕色颜料形成的化学链现在已经相当清楚，而导致红色形成的反应链几乎完全不是.
ICROSCOPIC observation, as well as solubility tests and studies of the M effects of gene substitutions, have shown that the normal, wild type eye color of Drosophila melafiogaster is due to the presence of two pigments, red and brown. These two pigments are the end products of two largely independent chains of reactions. Recent work on the genetic control of eye color in Drosophila was almost entirely confined to the reaction chain leading to the formation of brown pigment. The hormone-like diffusible substances derived from tryptophane and representing intermediate links of this chain were the most intensively studied phase of this process. The study of the reaction chain resulting in the formation of red pigment was on the contrary very much neglected and so was the study of the end products of both reaction chainsnamely, the red and brown pigments themselves. Both technical and theoretical factors were responsible for this uneven advance. Technically, the diffusible nature of the hormone-like substances makes them particularly accessible for a very direct experimental attack. The intermediate products involved in the formation of red pigment offer no such technical advantages. The origin of the red pigment, in so far as we know, is entirely intracellular and local. The study of the pigments themselves has encountered technical obstacles, chiefly in finding suitable solvents, which have greatly retarded the understanding of their chemical nature. Only lately a most promising study by BECKER (1939,1942) somewhat clarified the chemical nature of the pigments, but this lead was broken by BECKER’S death on the Russian front. Two theoretical considerations may be added to the above technical ones. In the early phases of the work under discussion it was plausible to assume a rather direct relationship between the diffusible substances and the genes controlling their production. It was a reasonable hope that, starting from the tangible diffusible substances, it would be easier to trace back to the genes the whole chain of intermediate reactions, connecting the genes with the characters they control. This possibility had a special appeal to certain investigators, while to others the diffusible substances were of particular interest as means for the discovery of spatial and temporal correlations in development. Whatever the reason in each particular case may have been, the net result is that the chain of reactions leading to the formation of brown pigment is now rather well defined, while that leading to the formation of red is almost entirely un-