CHARACTERIZATION OF DASYPYRUM-VILLOSUM (L) CANDARGY CHROMOSOMAL CHROMATIN BY MEANS OF IN-SITU RESTRICTION ENDONUCLEASES, FLUOROCHROMES, SILVER STAINING AND C-BANDING

The distribution of C-banded heterochromatin was determined in an inbr ed line of Dasypyrom villosum. Practically no difference in chromosome morphology or band distribution could be observed within the chromoso mes of the same pair. Heterochromatin bands, revealed by Giemsa bandin g, were characterized by means of their differential reaction to fluor ochromes, silver staining and in situ digestion with different restric tion endonucleases. The results clearly indicate that in D. villosum t wo different classes of heterochromatin with different chromosomal loc al-ization exist: one is evidenced by both C-banding and DAPI staining and has mainly telomeric distribution, the other is evidenced only by C-banding and has mainly centromeric distribution.