Hofmann Annemarie, Brünner Madeleine, Korge Günter
Institut für Biologie-Genetik, Freie Universität Berlin, Arnimallee 7, 14195, Berlin, Germany.
Chromosome Res. 2009;17(3):347-58. doi: 10.1007/s10577-009-9026-1. Epub 2009 Mar 20.
Gene expression goes along with changes in chromatin structure and is regulated by chromatin-modifying factors. If genes are transposed from their euchromatic position to the vicinity of heterochromatin, their expression can underly a position effect variegation (PEV). In Drosophila melanogaster a few genes are known that function in a gene dose-dependent manner as haplo-suppressors and triplo-enhancers of PEV or vice versa. The gene jumeaux (jumu) encodes a winged-helix transcription factor of multiple regulatory functions. A novel PEV test system for Drosophila melanogaster reveals that JUMU behaves as a haplo-suppressor/triplo-enhancer in different larval and adult tissues, but surprisingly behaves in the reverse manner as a haplo-enhancer/triplo-suppressor in larval and adult brains. Like jumu, the Su(var)3-9 gene also behaves as a haplo-suppressor/triplo-enhancer, but in our test system does not show any PEV effect in the brains.
基因表达与染色质结构的变化相伴，并受染色质修饰因子调控。如果基因从常染色质位置转座到异染色质附近，其表达可能会出现位置效应斑驳（PEV）。在黑腹果蝇中，已知有一些基因以基因剂量依赖的方式发挥作用，作为PEV的单倍体抑制因子和三倍体增强因子，反之亦然。jumeaux（jumu）基因编码一种具有多种调节功能的翼状螺旋转录因子。一种用于黑腹果蝇的新型PEV测试系统表明，JUMU在不同的幼虫和成虫组织中表现为单倍体抑制因子/三倍体增强因子，但令人惊讶的是，在幼虫和成虫大脑中，它的表现则相反，为单倍体增强因子/三倍体抑制因子。与jumu一样，Su(var)3-9基因也表现为单倍体抑制因子/三倍体增强因子，但在我们的测试系统中，它在大脑中未显示出任何PEV效应。
