Effective approaches for selecting nuclei in which a gene of interest is in an active state are necessary for studying spatial organization and gene expression regulation. In this work, a novel two-component genetic system was created for the parasegment-specific labeling of nuclei in which the regulatory domain iab-5, which stimulates the homeotic gene Abd-B, is active. The system is based on the integration of a transgene expressing the yeast GAL4 activator under the control of the minimal hsp70 gene promoter into the iab-5 domain, near the early embryonic enhancer. As a result, the iab-5 enhancer induces specific expression of GAL4, which strongly amplifies the expression of the mScarlet fluorescent protein, allowing for the efficient selection of labeled nuclei in which the iab-5 domain is activated. This approach can be used for the selection of target nuclei in which any regulatory element or gene of interest is in an active or repressed state.
Дериглазова et al. (Mon,) studied this question.