As I understand it, any gene on an exposed/unpacked region of a chromosome is continuously being expressed. Regulatory genes may increase or decrease the amount of protein synthesised due to its expression, but its expression is still fairly continuous.
Assuming I am correct, is there any regulatory framework by which genes are sequentially expressed. That is where the expression of one gene causes it to be turned off and another turned on?
For example, say some chromosome has genes A, B, and C. Is there a situation where gene A is expressed for some period, then gene B, and then gene C, but no more than one is ever expressed at once and they only are expressed in that order?
EDIT: I'll clarify that I don't expect genes which are suppressed to somehow still be accessible. Making them inaccessible is (as far as I know) how they are shut down. My point in mentioning how accessible genes are expressed is to highlight the uncontrolled nature of gene expression in relation to sequential gene expression and therefore to ask how the genetic machinery can get around this problem.