Heterochromatin organization in metaphase chromosomes and interphase nuclei of Dasypyrum breviaristatum (Lindb) Frederiksen

Abstract

Metaphase chromosomes of Dasypyrum breviaristatum (Lindb f) Frederiksen, a tetraploid wild species, were differentially stained with C-banding and fluorochromes in order to aquire information on heterochromatin chromosomal distribution and composition. DNA content and relative amount of nuclear heterochromatin were determined by cytophotometric analysis after Feulgen reaction. The results were compared to those of Dasypyrum villosum (L.) P. Candargy, a diploid species of the same genus. The achieved information indicate that D. breviaristatum and D. villosum differ in the composition, organization and distribution of heterochromatin, and may suggest that the telomeric regions of the chromosomes of the two species are more differentiated than the centromeric ones, as a result of a long lasting divergence between the two species.

Keywords

• Dasypyrum breviaristatum
• Dasypyrum villosum
• heterochromatin distribution
• chromatin organization
• nuclear DNA content
• phylogenetic relationships