Extremely faint expression was only observed in the posterior pharynx. To amplify the PQN-75:: GFP::3xFLAG signal, worms were fixed and stained green with M2 anti-flag and a blue DAPI/DNA costain, and still there was no evidence of germline expression. PQN-75 staining was exclusively in the pharynx, starting in the threefold stage of embryogenesis, becoming progressively more pronounced through larval development. Within the pharynx, PQN-75 was most abundant in the pharyngeal gland cells and could be observed in gland-cell processes that extend along the pharyngeal lumen. Interestingly, PQN-75 staining was not detected within the pharyngeal lumen, buccal cavity, or on the anterior cuticle. Instead, 77% (n=200) of larval-staged worms had varying amounts of PQN-75 aggregates throughout the pharynx, suggesting that gland cells secrete PQN-75 into the surrounding pharyngeal muscle.
The unc-33::gfp reporter is expressed in dividing neuroblasts at pre-comma embryonic stages. unc-33::gfp expression can be observed outside the nervous system in two amphid socket cells and weakly in non-neuronal pharyngeal cells.
A short gcy-33 promoter fragment is expressed in the BAG sensory neurons ( Yu et al., 1997 ), here was observed that an extended gcy-33::GFP reporter gene fusion was expressed in BAG, URX, AQR, and PQR neurons.