This expression construct was generated using theGateway/MultiSite Gateway systems (Invitrogen). A library of Gateway vectors (Invitrogen) was created to target expression of genes of interest to specific C. elegans cells. The promoter was used for RIM neuronal expression (D. Walker, H. Baylis, and W. Schafer, personal communication). The flp-18
coding region (1897bp) was cloned into Spe I/Kpn I sites of pENT95.75 vector usingthe following primers: F: aaaactagttttcagggttagacATGcaac, R: tttggtaccaatttacttccgtccgaatc. The cex-1p
1078bp region directly upstream to ATG was recombined into pDONR P2RP3(Supplementary Figure 2).