Effects of Mutations in the Drosophila melanogaster Rif1 Gene on the Replication and Underreplication of Pericentromeric Heterochromatin in Salivary Gland Polytene Chromosomes
| Autor: | Alexandra V. Kolodyazhnaya, Tatyana D. Kolesnikova, Galina V. Pokholkova, Viktoria V. Dovgan, Svetlana A. Romanenko, Veit Schubert, Dmitry Yu Prokopov, Igor F. Zhimulev |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
polytene chromosomes Heterochromatin Satellite DNA Telomere-Binding Proteins satellite DNA replication timing Article Salivary Glands 03 medical and health sciences SuUR 0302 clinical medicine Rif1 Endoreduplication Animals Drosophila Proteins underreplication Drosophila melanogaster lcsh:QH301-705.5 X chromosome Genetics Su(var)3-9 Replication timing Polytene chromosome biology heterochromatin Chromosome General Medicine biology.organism_classification 030104 developmental biology lcsh:Biology (General) Mutation Carrier Proteins 030217 neurology & neurosurgery |
| Zdroj: | Cells Cells, Vol 9, Iss 1501, p 1501 (2020) Volume 9 Issue 6 |
| ISSN: | 2073-4409 |
| Popis: | In Drosophila salivary gland polytene chromosomes, a substantial portion of heterochromatin is underreplicated. The combination of mutations SuURES and Su(var)3-906 results in the polytenization of a substantial fraction of unique and moderately repeated sequences but has almost no effect on satellite DNA replication. The Rap1 interacting factor 1 (Rif) protein is a conserved regulator of replication timing, and in Drosophila, it affects underreplication in polytene chromosomes. We compared the morphology of pericentromeric regions and labeling patterns of in situ hybridization of heterochromatin-specific DNA probes between wild-type salivary gland polytene chromosomes and the chromosomes of Rif1 mutants and SuUR Su(var)3-906 double mutants. We show that, despite general similarities, heterochromatin zones exist that are polytenized only in the Rif1 mutants, and that there are zones that are under specific control of Su(var)3-9. In the Rif1 mutants, we found additional polytenization of the largest blocks of satellite DNA (in particular, satellite 1.688 of chromosome X and simple satellites in chromosomes X and 4) as well as partial polytenization of chromosome Y. Data on pulsed incorporation of 5-ethynyl-2&prime deoxyuridine (EdU) into polytene chromosomes indicated that in the Rif1 mutants, just as in the wild type, most of the heterochromatin becomes replicated during the late S phase. Nevertheless, a significantly increased number of heterochromatin replicons was noted. These results suggest that Rif1 regulates the activation probability of heterochromatic origins in the satellite DNA region. |
| Databáze: | OpenAIRE |
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