Specific Mg2+ binding to AT-rich regions of chromatin in the evolution of eukaryotes
| Autor: | Riccardo Levi-Setti, Konstantin L. Gavrilov, Pamela L. Strissel, Reiner Strick |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
Polytene chromosome biology Topoisomerase General Physics and Astronomy Surfaces and Interfaces General Chemistry Condensed Matter Physics biology.organism_classification Molecular biology Surfaces Coatings and Films Cell biology Chromatin Divalent chemistry.chemical_compound Higher Order Chromatin Structure chemistry biology.protein Drosophila melanogaster Metaphase DNA |
| Zdroj: | Applied Surface Science. 252:6770-6773 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2006.02.271 |
| Popis: | At SIMS XIV, we reported SIMS evidence of specific Mg 2+ binding to the AT-rich regions of human metaphase chromosomes represented by G-bands. Subsequent Mg 2+ -depletion experiments supported a direct role for Mg 2+ in promoting and maintaining the higher order chromatin structure originating G-bands, possibly due to both Mg 2+ -DNA and Mg 2+ -protein interactions. An in-depth study, reported elsewhere, implicated also Ca 2+ in the maintenance of chromatin ultrastructure in the scaffold of mammalian chromosomes, in association with topoisomerase II. We examine here the association of Mg 2+ with AT-rich regions of chromatin in the chromosomes of the Indian muntjac deer (IMD), leading to conclusions similar to the above. To answer the question whether the presumed divalent cation role in the chromosomes of advanced eukaryotes had an evolutionary history to be traced back to earlier evolutionary stages, we have SIMS-mapped Ca 2+ and Mg 2+ in BrdU-labeled polytene chromosomes from the salivary gland of the Dipteran Drosophila melanogaster. Striking Ca 2+ and Mg 2+ SIMS banding patterns correlating with those of the Br label (a thymidine analogue) implicate unequivocally a close association of both these cations with the AT-rich regions of DNA for these primitive eukaryotes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect