ISSN:
1432-0886
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. In a variety of organisms, euchromatic genes brought into juxtaposition with pericentric heterochromatin show position-effect variegation (PEV), a silencing of gene expression in a subset of the cells in which the gene is normally expressed. Previously, a P-element mobilization screen identified transgenic Drosophila stocks showing PEV of an hsp70-white + reporter gene; transgenes in many of these stocks map to the chromocenter of polytene chromosome. A screen at an elevated temperature identified two stocks that under standard culture temperatures show complete repression of the hsp70-white + transgene. The transgenes in both cases map to the chromocenter of polytene chromosomes. Different types of middle repetitive elements are adjacent to seven pericentric transgenes; unique sequences are adjacent to two of the perimetric transgenes. All of the transgenes show suppression of PEV in response to a mutation in the gene encoding heterochromatin protein 1 (HP1). This suppression correlates with a more accessible chromatin structure. The results indicate that a pericentric transgene showing PEV can be associated with different types of DNA sequences, while maintaining a common association with the chromosomal protein HP1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004120050309
