Figure 1 The C. elegans Nogo-A/RTN4 homolog RET-1 is expressed in the nervous system. (A) Alignment of the C-terminus of C. elegans RET-1 with the Nogo-A/RTN4 homologs of mouse, rat and human. The RHD is highlighted in gray. Alignment was generated using ClustalW. (B) The
ret-1 locus comprises eight isoforms encoding predicted proteins of 204-3303 amino acids. All isoforms harbor an RHD in their C-termini. The deletion alleles (marked by red bars) used in this study (
gk242 and
tm390) both affect the RHD and produce frameshifts. The DNA sequence that encodes the RHD is marked by a black bar at the C terminus. We used
ret-1 isoform g.2 as a model to study the
ret-1 expression pattern and function. The
ret-1 isoform g.2 5000 bp promoter used to report expression (
ret-1isoformg.2prom::gfp-now written as
ret-1prom::gfp) is shown below the locus. (C-G) Expression of the transcriptional
ret-1prom::gfp reporter during embryonic and young adult stages. (C-F) At the bean stage,
ret-1prom::gfp is diffusely expressed (D); however, robust expression is observed in the twofold stage of the embryo in two head neurons (F). (C, E) DIC images of the fluorescent images shownin (D) and (F). Postembryonically,
ret-1prom::gfp is highly expressed in embryonic motor neurons [eMNs, white arrowheads in (G) and (H)] andhermaphrodite-specific neurons [HSNs, red arrowheads in (G)], the head [red arrowhead in (H) points to the nerve ring], and the tail. All images arelateral views, except the ventral view in (G). Anterior to the left. Bars, 10 um.