The discriminating fluorescence patterns of the chromosomes of Drosophila melanogaster

Abstract

Mitotic and salivary gland chromosomes of D. melanogaster show striking fluorescent patterns when stained with Quinacrine. In the salivary gland chromosomes there are up to five strongly fluorescing bands located on the fourth chromosome and at the proximal end of the X chromosome.—In mitotic cells the Y chromosome shows four fluorescent segments and other fluorescent regions are found proximally on the third pair and on the X chromosome. It is, therefore, possible to distinguish male and female interphase cells by their patterns of fluorescence.—A comparison between the position of heterochromatic, late replicating and fluorescing segments in the mitotic chromosomes, shows differences which demonstrate, for the first time, the chemical, morphological and genetical diversity of these three types of segments.