Dobzhansky T, Pavlovsky O, Andregg M
Genetics. 1975 Oct;81(2):357-67. doi: 10.1093/genetics/81.2.357.
Most strains of Drosophila pseudoobscura are neutral to light when tested in phototactic mazes. However, clear-cut photopositive and photogenative populations are obtained by selection over a series of generations. The genetic nature of the differences between the positive and negative populations has been studied in crosses in which the three large autosomes carried mutant markers. All chromosomes contain genes which influence the response to light. The third chromosome has the strongest effect, followed by the second, the X, and the fourth chromosomes. This seriation is not in proportion to the relative lengths of the chromosomes. Either the effective genes are not very numerous, or some of them exert stronger influences than others.
在趋光迷宫试验中,大多数拟暗果蝇品系对光呈中性反应。然而,通过连续几代的选择,可获得明显的趋光阳性和趋光阴性群体。在杂交实验中研究了阳性和阴性群体之间差异的遗传本质,在这些杂交中,三条大的常染色体带有突变标记。所有染色体都含有影响对光反应的基因。第三条染色体的影响最强,其次是第二条、X染色体和第四条染色体。这种顺序与染色体的相对长度不成比例。要么有效基因数量不多,要么其中一些基因的影响比其他基因更强。