Nucleolar organizer regions are associated with silver-stained chromatid cores in meiotic chromosomes of grasshoppers

Abstract

Silver staining was employed to study the expression and localization of nucleolar organizer regions (NORs) and the localization and development of chromatid cores during the meiotic divisions of the grasshopper Chorthippus jucundus. NORs appear as silver-stained dots on the short arms of the L2 and L3 chromosomes and are always associated with chromatid cores. This observation provides an excellent chromosome marker to analyze the behaviour of chromatid cores during meiosis. Since both structures (NORs and chromatid cores) show a close interrelationship, we have obtained further evidence on the changes of organization that meiotic chromosomes undergo between metaphase I and anaphase I.Key words: nucleolar organizer region, meiosis, chromatid cores, chromosome structure, silver staining.