The immune system of teleost zebrafish (Danio rerio) shows high similarity to mammalian counterparts
sharing many innate immune components including Toll-Like Receptors (TLRs), cytokines, chemokines
and complement molecules. As in mammals, zebrafish also contains the transcription factor NF-jB that
plays dualist roles in innate immunity and early development. Indeed NF-jB members are expressed in
different temporal patterns during the early stages of zebrafish embryogenesis indicating that each molecule
is involved in specific developmental events. In the present study we employ zebrafish as a model
to characterise the expression pattern and role of a novel NF-jB regulator, termed Cactin, in early development.
Cactin was first characterised in Drosophila as a new member of the Rel pathway that could
affect the generation of dorsal–ventral polarity. To explore the potential developmental role of Cactin
in zebrafish, we initially investigated its expression pattern and functional role during early embryonic
developmental stages. We detect Cactin expression at all stages of early development and knockdown
of Cactin by specific morpholino antisense oligonucleotides causes developmental abnormalities manifested
by an overall dysmorphic cellular organisation. These results indicate that Cactin has been highly
conserved during evolution and plays a key role in early embryonic development