Characteristic folding pattern of polytene chromosomes in Drosophila salivary gland nuclei

Abstract
A computer-based system for recording and analyzing light microscope images, combined with classical cytogenetic analysis, revealed the spatial organization of the giant chromosomes of Drosophila salivary gland cells. Each polytene chromosome arm folds up in a characteristic way, contacts the nuclear surface at specific sites and is topologically isolated from all other arms.