| Literature DB >> 11136231 |
Y M Moshkin1, A A Alekseyenko, V F Semeshin, A Spierer, P Spierer, G F Makarevich, E S Belyaeva, I F Zhimulev.
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.Entities:
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Year: 2001 PMID： 11136231 PMCID： PMC14628 DOI： 10.1073/pnas.98.2.570
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205