Bhadra U, Pal-Bhadra M, Birchler J A
Division of Biological Sciences, University of Missouri-Columbia 65211, USA.
Genetics. 1997 Jul;146(3):903-17. doi: 10.1093/genetics/146.3.903.
A second chromosomal trans-acting modifier, Lightener of white (Low), modulates the phenotypic expression of various alleles of the white eye color gene. This modifier has an unusually broad spectrum of affected genes including white, brown, scarlet and the eye developmental genes, Bar and Lobe. In addition, Low weakly suppresses position effect variegation. Northern blot hybridization with different X and autosomal probes reveals that Low modulates genes of independent expression patterns. Interestingly, many of the modulations of gene expression are developmentally restricted and differ in intensity between the sexes. Low also elevates the expression of the histone tandem repeats in three distinct developmental stages. A deficiency encompassing the histone cluster reduces their transcript levels and significantly alters the expression of some of the tested genes. Thus, Low is a modifier that plays a role in modulating the expression of genes governing various processes including pigment deposition, eye development, chromosomal proteins and position effect variegation.
第二个染色体反式作用修饰因子——白眼淡化因子（Low），可调节白眼颜色基因各种等位基因的表型表达。该修饰因子具有异常广泛的受影响基因谱，包括白眼、褐眼、猩红眼以及眼睛发育基因Bar和Lobe。此外，Low对位置效应斑驳有微弱的抑制作用。用不同的X染色体和常染色体探针进行Northern印迹杂交表明，Low调节具有独立表达模式的基因。有趣的是，许多基因表达的调节在发育过程中受到限制，并且在两性之间强度不同。Low还在三个不同的发育阶段提高组蛋白串联重复序列的表达。包含组蛋白簇的缺失会降低它们的转录水平，并显著改变一些测试基因的表达。因此，Low是一个在调节控制各种过程的基因表达中发挥作用的修饰因子，这些过程包括色素沉积、眼睛发育、染色体蛋白和位置效应斑驳。
