Nitric Oxide (NO) plays a key role in the induction of larval metamorphosis in several
invertebrate phyla. The inhibition of the NO synthase in Crepidula fornicata, a molluscan model for
evolutionary, developmental, and ecological research, has been demonstrated to block the initiation
of metamorphosis highlighting that endogenous NO is crucial in the control of this developmental
and morphological process. Nitric Oxide Synthase contributes to the development of shell gland,
digestive gland and kidney, being expressed in cells that presumably correspond to FMRF-amide,
serotoninergic and catecolaminergic neurons. Here we identified a single Nos gene in embryonic
and larval transcriptomes of C. fornicata and studied its localization during development, through
whole-mount in situ hybridization, in order to compare its expression pattern with that of other
marine invertebrate animal modelsF.C. was supported by a SZN OU PhD fellowship. M.T.-G. was supported by a predoctoral
fellowship (Ref. BES-2012-052214 MICINN) and by the short-term stays program EEBB-1-16-11411.
C.G. was funded by project no CGL2011-29916. S.D. was funded by the NOEVO SZN projec