Chromosome Structure: Euchromatin and Heterochromatin

Heterochromatin heterogeneity in Oedipoda germanica (Orthoptera) detected by in situ digestion with restriction endonucleases

“…3(a)). Finally, in slides treated with Taqi, discrete positive bands are obtained in the distal region of DISCUSSION During recent years several reports on the characterization of heterochromatin in fixed chromosomes after digestion with REs have appeared (for review, see Babu and Verma, 1987). Our results (i) confirm the capability of REs to digest S9 and the subparacentromeric region of chromosome M5 ( fig.…”

Characterization of different chromatin types in Mytilus galloprovincialis L. after C-banding, fluorochrome and restriction endonuclease treatments

“…Taking these data into account, we can assume that the positive CMA3 bands which are observed on the chromosomes of mussel are CMA3-stained NORs. These results suggest that the DNA heterochromatin of the heterochromatic telomeric block of chromosomes 3, 6 and 7: (i) is characterized by the presence of repetitive sequences composed of GC base pairs (GC-rich DNA); (ii) that these telomeric blocks are the chromosomal sites where the rDNAs involved in the NORs are cytologically located (not functionally located; see for review, Babu & Verma, 1987);and (iii), it is possible to infer that heterochromatin from C-bands, CMA3-bands and NORs are associated or overlap and that, consequently, these regions share a similar molecular structure.…”

Chromosomal heterochromatin differentiation in Salmo trutta with restriction enzymes

“…It is now an accepted fact that variability of constitutive heterochromatin appears to be an extended characteristic of vertebrates (Babu & Verma, 1987). As the result of recent advances in staining techniques it has become possible to recognize heterochromatin regions with great precision in several groups (see for review John, 1988).…”