Identification and Expression of TGF-β Smads in the ctenophore Pleurobranchia bachei

Abstract

The TGF-β superfamily of signaling pathways is key in regulating embryonic development (Heldin et al. 2009). It is known to be present in all metazoan lineages (Huminiecki 2009). Studying this pathway in the ctenophore Pleurobrachia bachei may allow insights into the recent placement of ctenophores as the most basal metazoan lineage (Dunn et al. 2008). Studying Smad4 expression in embryos will determine where the TGF-β pathway is active during development. Adult P. bachei were collected from Friday Harbor Laboratories in Friday Harbor, WA. They were spawned; embryos collected, fixed and stained using whole mount antibody staining. Expression patterns revealed possible maternal derivatives of Smad4 in early stage embryos as well as possible use of the TGF-β pathway as a neurotransmitter in larvae that have finished development.