Final answer:
The statement about Ey master regulators in Drosophila being able to activate their regulatory networks outside their normal location is true. These powerful regulators can initiate developmental programs even in atypical cellular contexts, demonstrating their profound influence on gene expression.
Step-by-step explanation:
The statement that master regulators such as Ey in Drosophila can activate their regulatory networks outside the normal location is true. Master regulators like Ey are potent transcription factors that can activate a suite of target genes necessary for certain developmental processes. These master regulatory genes, like the homeobox-containing gene Ey, can initiate broad programs of development, indicating their powerful role in the regulation of gene expression. In experiments, misexpression of such genes can lead to ectopic organ development, such as the formation of extra eyes in places where they wouldn't normally develop. This demonstrates the ability of such factors to override cellular context and initiate their specific developmental programs.
During Drosophila development, as with other organisms, the regulation of gene expression is crucial. Regulatory proteins must activate specific genes in particular cells to ensure proper development of organs and systems. The regulation is often complex, with many factors affecting gene expression including transcription factors like homeobox genes. These factors can act during various stages of gene expression, from controlling the binding of RNA polymerase to the promoter, to responding to external signals like hormones.