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Position effect variegation in yeast
Author(s) -
Tartof Kenneth D.
Publication year - 1994
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.950161004
Subject(s) - variegation (histology) , yeast , position (finance) , biology , genetics , business , finance
Classically, position effect variegation has been studied in Drosophila and results when a euchromatic gene is placed adjacent to either centromeric heterochromatin or to a telomeric domain. In such a circumstance expression of the locus variegates, being active in some cells and silent in others. Over the last few years a comparable phenomenon in yeast has been discovered. This system promises to tell us much about this curious behaviour. Indeed, experiments reported recently (1) indicate that the variegation of a yeast telomeric gene is cell‐cycle regulated. The results suggest the following model. During DNA replication there is a disassembly of chromatin that allows a competition between silencing factors and trans ‐activators to take place. Thus, reassembly of the domain may result in either the repression or the expression of the affected gene and, hence, produce a variegating phenotype.