A heat shock promoter drives expression of the cnc C isoform, starting at the Met residue at position 21 of the open reading frame. The construct contains 1230bp of 3' UTR.
Ectopic expression of cncC.hs at 6-8 hours of development results in highly penetrant defects in head development; mouth hooks are absent and the cirri and dorsal bridge are greatly reduced or absent. The median tooth is abnormally shaped. There are narrow lateralgraten in the normal position in the head, but there is also a sclerotic extension of the lateralgraten that may represent a duplication of lateralgraten or H-piece arms.