<P> The effects of miRNA dysregulation of gene expression also seem to be important in neuropsychiatric disorders, such as schizophrenia, bipolar disorder, major depressive disorder, Parkinson's disease, Alzheimer's disease and autism spectrum disorders . </P> <P> The translation of mRNA can also be controlled by a number of mechanisms, mostly at the level of initiation . Recruitment of the small ribosomal subunit can indeed be modulated by mRNA secondary structure, antisense RNA binding, or protein binding . In both prokaryotes and eukaryotes, a large number of RNA binding proteins exist, which often are directed to their target sequence by the secondary structure of the transcript, which may change depending on certain conditions, such as temperature or presence of a ligand (aptamer). Some transcripts act as ribozymes and self - regulate their expression . </P> <Ul> <Li> Enzyme induction is a process in which a molecule (e.g., a drug) induces (i.e., initiates or enhances) the expression of an enzyme . </Li> <Li> The induction of heat shock proteins in the fruit fly Drosophila melanogaster . </Li> <Li> The Lac operon is an interesting example of how gene expression can be regulated . </Li> <Li> Viruses, despite having only a few genes, possess mechanisms to regulate their gene expression, typically into an early and late phase, using collinear systems regulated by anti-terminators (lambda phage) or splicing modulators (HIV). </Li> <Li> GAL4 is a transcriptional activator that controls the expression of GAL1, GAL7, and GAL10 (all of which code for the metabolic of galactose in yeast). The GAL4 / UAS system has been used in a variety of organisms across various phyla to study gene expression . </Li> </Ul> <Li> Enzyme induction is a process in which a molecule (e.g., a drug) induces (i.e., initiates or enhances) the expression of an enzyme . </Li>

What are three ways that eukaryotic gene expression is regulated
find me the text answering this question