H3K9 Promotes Under-Replication of Pericentromeric Heterochromatin in Drosophila Salivary Gland Polytene Chromosomes
Autor: | Robin L. Armstrong, Taylor J.R. Penke, Daniel J. McKay, Robert J. Duronio, Brian D. Strahl, Samuel K Chao, A. Gregory Matera, Gabrielle M Gentile |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
DNA Replication
0301 basic medicine lcsh:QH426-470 Euchromatin Heterochromatin Centromere Methylation Salivary Glands Article Endoreplication Histones 03 medical and health sciences 0302 clinical medicine Genetics Animals Endoreduplication under-replication Heterochromatin organization Genetics (clinical) Pericentric heterochromatin Polytene Chromosomes Polytene chromosome biology fungi H4K16 heterochromatin Chromatin Cell biology lcsh:Genetics H3K9 Drosophila melanogaster 030104 developmental biology Histone biology.protein Drosophila Protein Processing Post-Translational 030217 neurology & neurosurgery |
Zdroj: | Genes Volume 10 Issue 2 Genes, Vol 10, Iss 2, p 93 (2019) |
ISSN: | 2073-4425 |
DOI: | 10.3390/genes10020093 |
Popis: | Chromatin structure and its organization contributes to the proper regulation and timing of DNA replication. Yet, the precise mechanism by which chromatin contributes to DNA replication remains incompletely understood. This is particularly true for cell types that rely on polyploidization as a developmental strategy for growth and high biosynthetic capacity. During Drosophila larval development, cells of the salivary gland undergo endoreplication, repetitive rounds of DNA synthesis without intervening cell division, resulting in ploidy values of ~1350C. S phase of these endocycles displays a reproducible pattern of early and late replicating regions of the genome resulting from the activity of the same replication initiation factors that are used in diploid cells. However, unlike diploid cells, the latest replicating regions of polyploid salivary gland genomes, composed primarily of pericentric heterochromatic enriched in H3K9 methylation, are not replicated each endocycle, resulting in under-replicated domains with reduced ploidy. Here, we employ a histone gene replacement strategy in Drosophila to demonstrate that mutation of a histone residue important for heterochromatin organization and function (H3K9) but not mutation of a histone residue important for euchromatin function (H4K16), disrupts proper endoreplication in Drosophila salivary gland polyploid genomes thereby leading to DNA copy gain in pericentric heterochromatin. These findings reveal that H3K9 is necessary for normal levels of under-replication of pericentric heterochromatin and suggest that under-replication at pericentric heterochromatin is mediated through H3K9 methylation. |
Databáze: | OpenAIRE |
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