I would like to express a microRNA in most tissues during the adult stage of C. elegans (say for example from day 4 to 8). What would be the best
promoter to use in my construct (to get a stable worm line)?
Is there any one in the C. elegans community that have some experience with this?
Although a bit more convoluted, one could achieve adult-specific pan-worm expression of a gene using the Q system (similar to the Gal4 system). You could express the QF transcriptional activator using any commonly used ubiquitous promoter. Putting the gene under control of the QUAS response element would result in the ubiquitous expression of your gene. Temporal control can be provided by including the QS repressor in the system, also under control of a ubiquitous promoter. QS will repress QF until quinic acid is added (I think that this can be included directly in the plates), and would allow induced, day 4 expression of the gene. The caveat to this proposed approach is that since you want to express a miRNA do you need a PolIII promoter, or would a PolII driven approach suffice?