Topographical changes in rye chromosome ultrastructure caused by the C-banding procedure

Abstract

The changes in the surface features of rye chromosome 1 induced by the C-banding procedure was investigated using the scanning electron microscope. Each step in the procedure produced significant changes in the surface topography of the chromosome and minor differences in its general morphology. The most noticeable alteration, chromosomes flattened and smooth, occurred when they were incubated in phosphate buffer without Leishman's stain. Since chromosomes not treated with barium hydroxide were uniformly stained, it seems probable that this alkali removes chromatin unselectively and that the C-bands produced here are due to a differential affinity of the heterochromatin to the stain. Key words: rye, heterochromatin, C-banding.