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The bithorax complex of Drosophila melanogaster: Underreplication and morphology in polytene chromosomes |
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Published in | Proceedings of the National Academy of Sciences of the United States of America. 2001, vol. 98, no. 2, p. 570-4 | |
Abstract | The level of polyteny of the Drosophila salivary gland chromosomes was determined throughout the chromosome region 89E1-4, the locus of the Bithorax Complex. A zone of underreplication spans the 300 kb of DNA from the Ubx to Abd-B loci. From the centromere proximal end of the complex, a 70-kb-long gradual decrease of polytenization starts with the Ubx transcription unit and, after a floor corresponding to the abd-A locus, raises gradually back to the maximum over 70 kb in the region of the Abd-B transcription unit. In flies carrying the mutation Suppressor of DNA Underreplication [Su(UR)ES], the underreplication of the Bithorax Complex is fully suppressed. In the wild type, the Bithorax Complex forms a weak point featuring thinner bands separated by clefts or constrictions. In Su(UR)ES strain in contrast, the 89E1-4 band looks like a single solid band consisting of homogenous dense material. We speculate that the wild-type Su(UR)ES protein hampers DNA replication of silenced domains and leads to their underreplication in salivary gland polytene chromosomes. | |
Keywords | Animals — Chromosomes/genetics/ultrastructure — DNA Replication — DNA-Binding Proteins/genetics — Drosophila Proteins — Drosophila melanogaster/genetics/growth & development/ultrastructure — Gene Expression Regulation — Gene Silencing — Genes, Homeobox — Genes, Insect — Genes, Suppressor — Heterochromatin/genetics/ultrastructure — Homeodomain Proteins/genetics — Insect Proteins/genetics/physiology — Larva — Microscopy, Electron — Nuclear Proteins — Salivary Glands/ultrastructure — Transcription Factors | |
Identifiers | PMID: 11136231 | |
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Citation (ISO format) | MOSHKIN, Yuri M. et al. The bithorax complex of Drosophila melanogaster: Underreplication and morphology in polytene chromosomes. In: Proceedings of the National Academy of Sciences of the United States of America, 2001, vol. 98, n° 2, p. 570-4. doi: 10.1073/pnas.021353598 https://archive-ouverte.unige.ch/unige:9878 |