Through rDNA, the distribution pattern and
constitutive heterochromatin regions between morphotypes can be described and compared (Zheng, 2015).
nasutus from different countries, because all specimens showed the same karyotype, the same morphological characteristics for the autosomes and sex chromosomes and the same pattern of
constitutive heterochromatin (Table 1).
C-banding of mitotic metaphase revealed
constitutive heterochromatin blocks (thin C-bands) in the paracentromeric region in most chromosomal elements, with the exception of one small pair of autosomes (thick C-bands).
CBG-banding (Figure 1) in ACU revealed
constitutive heterochromatin in the centromeric regions of all chromosomes, except in pair 5 and in the Y chromosome.
Approximately 15-20% of this non-coding part of human DNA is
constitutive heterochromatin. There are two types of
constitutive heterochromatin: C- and Q-heterochromatin.
The researchers looked in detail at the mysterious tightly packed portions of the genome, called
constitutive heterochromatin.
2011), the principal component of the
constitutive heterochromatin. The C-banding technique confirmed the low amount of heterochromatin when using modern genome sequencing techniques.
By using C-banding
constitutive heterochromatin regions were observed on the centromeres of several chromosomes in all species.
Constitutive heterochromatin and nucleolus organizer regions (NORs) were detected by the techniques of C-banding [25] and silver staining of nucleolar organizer regions [26], respectively.
Trimethylated H3K9 (H3K9me3) is a highly conserved histone post-translational modification and is commonly linked to both facultative and
constitutive heterochromatin formation and transcriptional repression.
C-band results showed that all
constitutive heterochromatin was confined to the X chromosome, differing from the pattern observed in Cavia and Galea.
Detection of
constitutive heterochromatin (C-banding) was performed according to Sumner (1972), with some minor modifications.