I am wondering how do genes become sex-biased? that is, how does a gene evolve expression which is regulated in a sex-specific manner (assuming no effect from sex-limited Y/W chromosomes).
I understand that gene duplication can lead to two sex-limited genes, the derived being expressed in one sex and the ancestral being expressed in the other.
Can the sex determining cascade cause sex-biased expression of a single locus? My thinking is that upstream differences between males and females might bring about regulatory opportunity to loci under sexually antagonistic selection over expression level. For example, if males favour upregulation in a locus, males who evolve some kind of transcription factor affecting that locus which responds to male-specific isoforms of DSX (in Drosophila), which could then cause the antagonistically selected locus to be more highly expressed in males without producing a negatively selected correlated response in females.
Is this correct? Are there other ways?
(Note: I'm looking for a clear explanation of the mechanics behind sex biased gene expression. Drosophila examples would be of particular worth)