CONSTITUTIVE HETEROCHROMATIN, NOR LOCATION AND FISH IN THE GRASSHOPPER XYLEUS-ANGULATUS (ROMALEIDAE)

C-banding, fluorochrome staining, silver staining and fluorescence in situ hybridization (FISH) were used to characterization of the meiotic chromosomes in the grasshopper Xyleus angulatus. The C-banding patter n showed perincentromeric heterochromatin blocks in all chromosomes, i nterstitial blocks in the L-1, L-2 and L-3 pairs and distal blocks in medium and small-sized pairs. CMA(3)/DA staining revealed that these h eterochromatic regions were characterized by high content of GC bases pairs. The ribosomal DNA probe (pTa71) showed strong hybridization sig nal in the pericentromeric regions at bivalents L-3, M-4 and X chromos ome, corresponding to the silver-stained chromosomal positions of acti ve NORs and the heterochromatic area CMA(3)+ of these chromosomes.