Genetics, Vol 147, 1181-1190, Copyright © 1997

INVESTIGATIONS

Transgene Repeat Arrays Interact With Distant Heterochromatin and Cause Silencing in cis and trans

D. R. Dorer and S. Henikoff
Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024

Tandem repeats of Drosophila transgenes can cause heterochromatic variegation for transgene expression in a copy-number and orientation-dependent manner. Here, we demonstrate different ways in which these transgene repeat arrays interact with other sequences at a distance, displaying properties identical to those of a naturally occurring block of interstitial heterochromatin. Arrays consisting of tandemly repeated white transgenes are strongly affected by proximity to constitutive heterochromatin. Moving an array closer to heterochromatin enhanced variegation, and enhancement was reverted by recombination of the array onto a normal sequence chromosome. Rearrangements that lack the array enhanced variegation of white on a homologue bearing the array. Therefore, silencing of white genes within a repeat array depends on its distance from heterochromatin of the same chromosome or of its paired homologue. In addition, white transgene arrays cause variegation of a nearby gene in cis, a hallmark of classical position-effect variegation. Such spreading of heterochromatic silencing correlates with array size. Finally, white transgene arrays cause pairing-dependent silencing of a non-variegating white insertion at the homologous position.

This article has been cited by other articles:

				K. Sha and A. Fire Imprinting Capacity of Gamete Lineages in Caenorhabditis elegans Genetics, August 1, 2005; 170(4): 1633 - 1652. [Abstract] [Full Text] [PDF]

				R. Thakar and A. K. Csink Changing chromatin dynamics and nuclear organization during differentiation in Drosophila larval tissue J. Cell Sci., March 1, 2005; 118(5): 951 - 960. [Abstract] [Full Text] [PDF]

				D. Bushey and J. Locke Mutations in Su(var)205 and Su(var)3-7 Suppress P-Element-Dependent Silencing in Drosophila melanogaster Genetics, November 1, 2004; 168(3): 1395 - 1411. [Abstract] [Full Text] [PDF]

				B. T. Sage and A. K. Csink Heterochromatic Self-Association, a Determinant of Nuclear Organization, Does Not Require Sequence Homology in Drosophila Genetics, November 1, 2003; 165(3): 1183 - 1193. [Abstract] [Full Text] [PDF]

				V. J. Mutskov, C. M. Farrell, P. A. Wade, A. P. Wolffe, and G. Felsenfeld The barrier function of an insulator couples high histone acetylation levels with specific protection of promoter DNA from methylation Genes & Dev., June 15, 2002; 16(12): 1540 - 1554. [Abstract] [Full Text] [PDF]

				H. Schrem, J. Klempnauer, and J. Borlak Liver-Enriched Transcription Factors in Liver Function and Development. Part I: The Hepatocyte Nuclear Factor Network and Liver-Specific Gene Expression Pharmacol. Rev., March 1, 2002; 54(1): 129 - 158. [Abstract] [Full Text] [PDF]

				S. Ronsseray, A. Boivin, and D. Anxolabehere P-Element Repression in Drosophila melanogaster by Variegating Clusters of P-lacZ-white Transgenes Genetics, December 1, 2001; 159(4): 1631 - 1642. [Abstract] [Full Text] [PDF]

				R. A. Martienssen and V. Colot DNA Methylation and Epigenetic Inheritance in Plants and Filamentous Fungi Science, August 10, 2001; 293(5532): 1070 - 1074. [Abstract] [Full Text] [PDF]

				K. A. Maggert and G. H. Karpen The Activation of a Neocentromere in Drosophila Requires Proximity to an Endogenous Centromere Genetics, August 1, 2001; 158(4): 1615 - 1628. [Abstract] [Full Text] [PDF]

				E. Lebrun, E. Revardel, C. Boscheron, R. Li, E. Gilson, and G. Fourel Protosilencers in Saccharomyces cerevisiae Subtelomeric Regions Genetics, May 1, 2001; 158(1): 167 - 176. [Abstract] [Full Text]

				L. V. Sidorenko and T. Peterson Transgene-Induced Silencing Identifies Sequences Involved in the Establishment of Paramutation of the Maize p1 Gene PLANT CELL, February 1, 2001; 13(2): 319 - 335. [Abstract] [Full Text]

				C. D. Day, E. Lee, J. Kobayashi, L. D. Holappa, H. Albert, and D. W. Ow Transgene integration into the same chromosome location can produce alleles that express at a predictable level, or alleles that are differentially silenced Genes & Dev., November 15, 2000; 14(22): 2869 - 2880. [Abstract] [Full Text]

				E. V. Tolchkov, V. I. Rasheva, S. Bonaccorsi, T. Westphal, and V. A. Gvozdev The Size and Internal Structure of a Heterochromatic Block Determine Its Ability to Induce Position Effect Variegation in Drosophila melanogaster Genetics, April 1, 2000; 154(4): 1611 - 1626. [Abstract] [Full Text]

				P. B. Talbert and S. Henikoff A Reexamination of Spreading of Position-Effect Variegation in the white-roughest Region of Drosophila melanogaster Genetics, January 1, 2000; 154(1): 259 - 272. [Abstract] [Full Text]

				J. Hsieh, J. Liu, S. A. Kostas, C. Chang, P. W. Sternberg, and A. Fire The RING finger/B-Box factor TAM-1 and a retinoblastoma-like protein LIN-35 modulate context-dependent gene silencing in Caenorhabditis elegans Genes & Dev., November 15, 1999; 13(22): 2958 - 2970. [Abstract] [Full Text]

				A. P. Wolffe and M. A. Matzke Epigenetics: Regulation Through Repression Science, October 15, 1999; 286(5439): 481 - 486. [Abstract] [Full Text]

				G. L. Sass and S. Henikoff Pairing-Dependent Mislocalization of a Drosophila brown Gene Reporter to a Heterochromatic Environment Genetics, June 1, 1999; 152(2): 595 - 604. [Abstract] [Full Text]

				Y. S. Rong and K. G. Golic Dominant Defects in Drosophila Eye Pigmentation Resulting From a Euchromatin-Heterochromatin Fusion Gene Genetics, December 1, 1998; 150(4): 1551 - 1566. [Abstract] [Full Text]

				A. K. Csink and S. Henikoff Large-scale Chromosomal Movements During Interphase Progression in Drosophila J. Cell Biol., October 5, 1998; 143(1): 13 - 22. [Abstract] [Full Text] [PDF]

				M.-C. Chaboissier, A. Bucheton, and D. J. Finnegan Copy number control of a transposable element, the I factor, a LINE-like element in Drosophila PNAS, September 29, 1998; 95(20): 11781 - 11785. [Abstract] [Full Text] [PDF]