In addition to recapitulating previously reported expression patterns [in the gonad from mid-L1 larval stage until around the L1/L2 molt in both sexes and from the L3 larval stage through adult in the hermaphrodite gonad in the spermatheca and sheath cells], this new construct revealed expression of FKH-6::GFP in 2-4 male gonadal cells in the L3 larval stage. This is the first report of FKH-6 expression in males after the L1/L2 molt. The expression of FKH-6::GFP in the gonad of the L3 male is reproducible, appearing in 54 of the 58 male animals observed during this time period, but the expression is short-lived, and coincides with the period when the proximal region of the migrating male gonad is extending past the distal tip of the gonad.
Postembryonic expression of a functional gfp-tagged fkh-2 gene was restricted to the nuclei of the AWB neurons, with less consistent expression in additional chemosensory neurons.
Consistent with previous findings (Kim and Li, 2004), we found that flp-20 is expressed in the TRNs (ALM, AVM, PLM, PVM), along with a few other neurons (ASE, LUA, and PVC).
The expression pattern of Pncr-2/GFP/49.26 differs from what Li et al. (2004) report in that expression in the gonadal sheath was not observed but was observed in the ventral nerve cord.
We inserted an in-frame gfp cassette into the endogenous tmc-1 locus using the CRISPR/Cas9 knockin method (Li et al., 2015). Using this approach, we observed TMC-1 expression in vulval muscles as well as several head neurons and body wall muscles.
The anti-PAT-6/actopaxin antibody stains body wall muscle cell attachments of wild-type and pat-6 embryos that have been rescued by a functional pat-6::Green Fluorescent Protein (GFP) transgene.
In double immunostaining experiments with anti-myosin and anti-MIG-6 antisera, MIG-6 appears to be localized near the muscle surface. MIG-6 in larvae also localizes to intestine, pharynx and gonad basement membranes.