Probes of chromatin accessibility in the Drosophila bithorax complex respond differently to Polycomb‐mediated repression.

The Polycomb group (PcG) of genes are required for maintenance of the repressed state of the homeotic genes in Drosophila. There are similarities between the PcG repression and mating‐type silencing in yeast or heterochromatic position effect in Drosophila, which suggest that PcG repression may involve a highly compacted chromatin structure. To test for such a structure, heterologous DNA‐ binding proteins were used as probes for DNA accessibility in Drosophila embryos. Binding sites for the yeast transcriptional activator GAL4 and for bacteriophage T7 RNA polymerase were inserted into the bithorax (bx) regulatory region of the endogenous Ultrabithorax (Ubx) gene, which is regulated by the PcG. Ubiquitously expressed GAL4 protein directs transcription through its binding sites only in the posterior segments where the bx region is active. The block to GAL4 activation in the more anterior segments is dependent on Polycomb (Pc) function. In contrast, T7 RNA polymerase can transcribe from its target promoter in all segments of the embryo. Thus, Pc‐mediated repression blocks activated polymerase II transcription, but does not simply exclude all proteins.

[1]  R. Paro,et al.  Drosophila Polycomb‐group regulated chromatin inhibits the accessibility of a trans‐activator to its target DNA. , 1995, The EMBO journal.

[2]  S. Elgin,et al.  Position effect variegation in Drosophila is associated with an altered chromatin structure. , 1995, Genes & development.

[3]  W. Bender,et al.  Comparison of germline mosaics of genes in the Polycomb group of Drosophila melanogaster. , 1995, Genetics.

[4]  R. Hodgetts,et al.  Targeting of an enhancer trap to vestigial. , 1994, Developmental biology.

[5]  V. Pirrotta,et al.  White gene expression, repressive chromatin domains and homeotic gene regulation in Drosophila , 1994, BioEssays : news and reviews in molecular, cellular and developmental biology.

[6]  W. Bender,et al.  Enhancer point mutation results in a homeotic transformation in Drosophila. , 1994, Science.

[7]  G. Gloor,et al.  Efficient copying of nonhomologous sequences from ectopic sites via P-element-induced gap repair , 1994, Molecular and cellular biology.

[8]  R. Morse.  Nucleosome disruption by transcription factor binding in yeast. , 1993, Science.

[9]  R. Paro,et al.  Mechanisms of heritable gene repression during development of Drosophila. , 1993, Current opinion in cell biology.

[10]  T. Jenuwein,et al.  The immunoglobulin mu enhancer core establishes local factor access in nuclear chromatin independent of transcriptional stimulation. , 1993, Genes & development.

[11]  Alan P. Wolffe,et al.  A positive role for histone acetylation in transcription factor access to nucleosomal DNA , 1993, Cell.

[12]  J. Rine,et al.  Silencers, silencing, and heritable transcriptional states. , 1992, Microbiological reviews.

[13]  R. Lehmann,et al.  Localization of nanos RNA controls embryonic polarity , 1992, Cell.

[14]  M. Bienz,et al.  Sharp anterior boundary of homeotic gene expression conferred by the fushi tarazu protein. , 1992, The EMBO journal.

[15]  P. Spierer,et al.  Position effect variegation and chromatin proteins , 1992, BioEssays : news and reviews in molecular, cellular and developmental biology.

[16]  I. Herskowitz,et al.  Characterization of the yeast SWI1, SWI2, and SWI3 genes, which encode a global activator of transcription , 1992, Cell.

[17]  Thomas C. Kaufman,et al.  brahma: A regulator of Drosophila homeotic genes structurally related to the yeast transcriptional activator SNF2 SWI2 , 1992, Cell.

[18]  W. Bender,et al.  Ten different Polycomb group genes are required for spatial control of the abdA and AbdB homeotic products. , 1992, Development.

[19]  A. Klar,et al.  Active genes in budding yeast display enhanced in vivo accessibility to foreign DNA methylases: a novel in vivo probe for chromatin structure of yeast. , 1992, Genes & development.

[20]  M. Roberge,et al.  Nucleosome arrays inhibit both initiation and elongation of transcripts by bacteriophage T7 RNA polymerase. , 1992, Journal of molecular biology.

[21]  N. Nassif,et al.  Targeted gene replacement in Drosophila via P element-induced gap repair , 1991, Science.

[22]  T. Orr-Weaver,et al.  The regulation of the cell cycle during Drosophila embryogenesis: the transition to polyteny. , 1991, Development.

[23]  J. Workman,et al.  Facilitated binding of GAL4 and heat shock factor to nucleosomal templates: differential function of DNA-binding domains. , 1991, Genes & development.

[24]  V. Pirrotta,et al.  The bx region enhancer, a distant cis‐control element of the Drosophila Ubx gene and its regulation by hunchback and other segmentation genes. , 1991, The EMBO journal.

[25]  B. Turner,et al.  Histone acetylation and control of gene expression. , 1991, Journal of cell science.

[26]  A. Wolffe,et al.  Initiation of transcription on nucleosomal templates. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[27]  E. Sánchez-Herrero,et al.  Spatially ordered transcription of regulatory DNA in the bithorax complex of Drosophila. , 1989, Development.

[28]  G. Rubin,et al.  cis-acting DNA sequence requirements for P-element transposition. , 1989, Genes & development.

[29]  M. Ptashne.  How eukaryotic transcriptional activators work , 1988, Nature.

[30]  W. Engels,et al.  A stable genomic source of P element transposase in Drosophila melanogaster. , 1988, Genetics.

[31]  J. Hooper,et al.  Homeotic gene function in the muscles of Drosophila larvae , 1986, The EMBO journal.

[32]  M. Levine,et al.  Spatial regulation of antennapedia and bithorax gene expression by the Polycomb locus in Drosophila , 1986, Cell.

[33]  M. Wilcox,et al.  Regulation of the distribution of Ultrabithorax proteins in Drosophila , 1985, Nature.

[34]  M. Akam,et al.  Altered distributions of Ultrabithorax transcripts in extra sex combs mutant embryos of Drosophila. , 1985, The EMBO journal.

[35]  T. Grigliatti,et al.  Histone Gene Multiplicity and Position Effect Variegation in DROSOPHILA MELANOGASTER. , 1983, Genetics.

[36]  E. Lewis.  A gene complex controlling segmentation in Drosophila , 1978, Nature.

[37]  V. Ingram,et al.  n-Butyrate causes histone modification in HeLa and Friend erythroleukaemia cells , 1977, Nature.

[38]  J. Simon,et al.  Locking in stable states of gene expression: transcriptional control during Drosophila development. , 1995, Current opinion in cell biology.

[39]  R. Paro,et al.  The Polycomb protein shares a homologous domain with a heterochromatin-associated protein of Drosophila. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[40]  T. Grigliatti.  Position-effect variegation--an assay for nonhistone chromosomal proteins and chromatin assembly and modifying factors. , 1991, Methods in cell biology.

[41]  R. Paro,et al.  Imprinting a determined state into the chromatin of Drosophila. , 1990, Trends in genetics : TIG.

[42]  J. McKeon,et al.  Interactions of the Polycomb group of genes with homeotic loci of Drosophila , 2022 .