Distamycin A/DAPI staining of heterochromatin in male meiosis of man

Abstract

The sequential staining with distamycin A/DAPI provides an ideal method for studying the behaviour of heterochromatic regions in human male meiosis. The various meiotic and postmeiotic stages were found to have different staining qualities. Although all heterochromatic regions in human pachytene cells show specific DA/DAPI fluorescence, bright and clearly stained heterochromatic blocks can be distinguished from small DA/DAPI spots. Pachytene nuclei exhibit associations between heterochromatic regions of non-homologous bivalents. The heterochromatin of bivalent 9 generally presents as a cluster of small, discrete bodies. The heterochromatic regions of chromosomes 1, 9, 15, 16 and Y are preferentially stained at diakinesis and metaphase of the second meiotic division. The specific DA/DAPI staining disappears with the progressive volume reduction of middle and late spermatid nuclei. The heterochromatin of the chromatids fuses to form a large chromocenter during spermatid differentiation.