Figure 5. NAS-37::GFP protein is secreted. A C-terminal GFP fusion to NAS-37 expressed under the
nas-37 promoter shows localization of NAS-37 protein. An overlay of a confocal projection of GFP fluorescence with the corresponding DIC image of an L4 worm (A) shows that NAS-37 is found in the cuticle and accumulates at the anterior end of the worm. It is also strongly expressed in the excretory duct cell (arrowhead). A confocal micrograph of the adult vulva (B) shows that NAS-37 accumulates in the vulval cuticle. A confocal projection of more lateral cuticle of an L4 animal (C) shows that NAS-37 is concentrated in the annular rings of the anterior cuticle, as well as in the lateral cuticle. A view of the posterior region of an L4 animal (D) shows that NAS-37 accumulates in the cuticle of the rectum. Fluorescence in the gut is due to autofluorescent particles and is not NAS-37::GFP. A confocal micrograph of a molted cuticle (E) shows that the NAS-37 protein accumulates in the anterior (arrowhead) and posterior (arrow) ends of the shed cuticle.