PTC-3::GFP expression is highly dynamic. In particular, high levels of PTC-3::GFP were detected in the hypodermis prior to hatching; expression also intensified in the hypodermis prior to each larval molt. PTC-3::GFP was also detected in the excretory duct, which is involved in maintaining ionic and osmotic regulation (Nelson and Riddle, 1984).
The C+C enhancer (pOK17.21) activates frequent expression in all pharyngeal muscles. the C+C enhancer also activates expression in non-muscle cells in the pharynx. Expression induced by the C+C enhancer was observed in all pharyngeal cell types including gland cells, neurons and marginal cells as well as muscles. These results define C as an organ-specific subelement.