Chromatin structure in pre- and postblastula embryos of Drosophila
TL;DR: The chromatin structure of cleavage-stage embryos detected by these tests appears to be essentially the same as that of older embryos, both in general, and at specific loci.
About: This article is published in Developmental Biology.The article was published on 1983-09-01. It has received 20 citations till now. The article focuses on the topics: DNase I hypersensitive site & Chromatin.
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TL;DR: Eukaryotic chromatin has a dynamic, complex hierarchical structure and the chromatin structure of various DNA regulatory sequences, such as promoters, terminators and enhancers, appears to partially regulate transcriptional activity.
338 citations
TL;DR: Nonhistone Proteins at DH Sites and Establishing and Maintaining a DH Site are discussed.
Abstract: DNASE I HYPERSENSITIVE SITES . Occurrence of DH Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DH Sites Are Associated with Specific DNA Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Altered DNA Conformation May Be Associated with DH Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . Nonhistone Proteins at DH Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Establishing and Maintaining a DH Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
210 citations
TL;DR: It is proposed that Zld primes enhancers by lowering the high nucleosome barrier just enough to assist TFs in accessing their binding motifs and promoting spatially controlled enhancer activation if the right patterning TFs are present.
Abstract: The Drosophila genome activator Vielfaltig (Vfl), also known as Zelda (Zld), is thought to prime enhancers for activation by patterning transcription factors (TFs). Such priming is accompanied by increased chromatin accessibility, but the mechanisms by which this occurs are poorly understood. Here, we analyze the effect of Zld on genome-wide nucleosome occupancy and binding of the patterning TF Dorsal (Dl). Our results show that early enhancers are characterized by an intrinsically high nucleosome barrier. Zld tackles this nucleosome barrier through local depletion of nucleosomes with the effect being dependent on the number and position of Zld motifs. Without Zld, Dl binding decreases at enhancers and redistributes to open regions devoid of enhancer activity. We propose that Zld primes enhancers by lowering the high nucleosome barrier just enough to assist TFs in accessing their binding motifs and promoting spatially controlled enhancer activation if the right patterning TFs are present. We envision that genome activators in general will utilize this mechanism to activate the zygotic genome in a robust and precise manner.
157 citations
TL;DR: Studies of the heat-shock genes are reviewed, illustrating the formation of a specific nucleosome array at an activatable promoter, and information is presented on the roles of DNA-binding factors and energy-dependent chromatin remodeling machines in facilitating assembly of an appropriate structure.
92 citations
Cites background from "Chromatin structure in pre- and pos..."
...…monomers, dimers, trimers, etc. of a relatively uniform size) in nuclei from older course of evolution, one might select for DNA sequences that have different ‘affinities’ for nucleosome formation,embryos, but a ‘smeared’ nucleosomal array from preblastoderm embryos (Lowenhaupt et al., 1983)....
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Book•
01 Feb 1984
TL;DR: A novel system using the Expression of Chloramphenicol Acetyltransferase in Eukaryotic Cells Allows the Quantitative Study of Promoter Elements and Nucleotide Sequence and Structure Determination of Rabbit 18 S Ribosomal RNA.
Abstract: 1 Some Observations on DNA Structure and Chromatin Organization at Specific Loci in Drosophila melanogaster -- 2 Expression of Transferred Thymidine Kinase Genes in Mouse L Cells: Evidence for Control by DNA Methylation -- 3 Pattern of Histone-Variant Synthesis and Implications for Gene Regulation -- 4 Mechanisms for Evolutionary Divergence within the Prolactin Gene Family -- 5 Cloning and Structure Analysis of Histocompatibility Class I and Class II Genes -- 6 The Production of Transgenic Mice -- 7 Human and Mouse Globin-Gene Sequences Introduced into Mice by Microinjection of Fertilized Mouse Eggs -- 8 A Novel System Using the Expression of Chloramphenicol Acetyltransferase in Eukaryotic Cells Allows the Quantitative Study of Promoter Elements -- 9 Ti Plasmids as Gene Vectors for Plants -- 10 Activity of a Chick Collagen Gene in Heterologous and Homologous Cell-Free Extracts -- 11 Transcription of Ribosomal RNA Genes in Mouse and Frog -- 12 Nucleotide Sequence and Structure Determination of Rabbit 18 S Ribosomal RNA.
48 citations
References
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Book•
01 Jan 1976
TL;DR: This is the first attempt since 1925 to publish a comprehensive account of the biology and genetics of Drosophila and it aims to collate the dauntingly large literature on the subject and to make more accessible the private language ot the Dosophilist.
Abstract: Studies with Drosophila, in particular with Drosophila melanogaster, have contributed more to our understanding of heredity than studies with any other eukaryotes. It is genetically the best known "higher" organism; this means not only that a greater number of mutations are known in Drosophila than in other organisms, but also that we have an unrivalled ability to manipulate its chromosomes and mutations to experimental advantage, Drosophila is the organism of choice for studies of development, behaviour and evolution as well as the formal mechanisms of genetics. Current research ranges from problems in "pure genetics" to sophisticated studies in neurobiology and ecology. Surprisingly, this is the first attempt since 1925 to publish a comprehensive account of the biology and genetics of Drosophila. It aims to collate the dauntingly large literature on the subject and to make more accessible the private language ot the Drosophilist. In this way the work will be of value both to established research workers and to biologists in general. This remarkable and ambitious work has been divided into three series of volumes. Volumes la, lb and lc deal with the formal genetics of Drosophila, Volume 2 deals with its biology and development and Volume 3 with its evolution and ecology. These volumes will prove an invaluable source of reference for Drosophilists, advanced students of genetics and for biologists, entomologists and zoologists with an interest in Drosophila research.
2,942 citations
TL;DR: Many specific sites in Drosophila chromatin are hypersensitive to DNase I and the positions of such sites were mapped along the regions of the genome coding for two heat shock proteins.
Abstract: Many specific sites in Drosophila chromatin are hypersensitive to DNase I. The positions of such sites were mapped along the regions of the genome coding for two heat shock proteins. Such sites lie at the 5' ends of heat shock genes and may function as elements for recognition by molecules which regulate gene activity.
968 citations
TL;DR: A simple bifunctional molecule, methidiumpropyl-EDTA (MPE), which contains the DNA intercalator methidium covalently bound by a short hydrocarbon tether to the metal chelator EDT A efficiently produces single-Strand breaks and some double-strand breaks in double helical DNA.
Abstract: We report the synthesis of a simple bifunctional molecule, methidiumpropyl-EDTA (MPE) (1), which contains the DNA intercalator methidium covalently bound by a short hydrocarbon tether to the metal chelator EDT A. In the presence of ferrous ion and oxygen this reagent efficiently produces single-strand breaks and some double-strand breaks in double helical DNA.
396 citations
TL;DR: All rRNA loci, whether having complete or incomplete gradients, exhibit high densities of nascent transcripts per unit length, suggesting that the rate of chromatin transcription, rather than the RNA polymarase I pool size, limits rRNA synthesis on individual genes.
379 citations
TL;DR: Restriction enzyme cleavage of the fragments generated indicates that the preferential DNAase I cleavage sites in chromatin are position-specific, and this nuclease also cleaves at position- specific sites.
368 citations