RING finger protein 11 (RNF11) is a novel regulator of immunity and cell survival via ubiquitination process in mammalian cells whereas its vertebrate embryonic roles are undefined. Here, we are reporting the isolation, expression and functional roles of an RNF11 orthologue, Rnf11-like in zebrafish embryos. Zebrafish Rnf11-like is composed of 154 amino acids containing RING-H2-finger domain in the C-terminal region and PY-motif. Spatiotemporal expression patterns of rnf11-like indicate that rnf11-like is expressed maternally and zygotically throughout embryogenesis. However, rnf11-like transcripts are present specifically in the presomatic mesoderm (PSM), and later in the brain and retina. Knock-down of Rnf11-like using rnf11-like-specific morpholino causes cell death and developmental defects in the posterior somites, elevating transcripts of NF-kappa B target gene, ikk1, a negative regulator of NF-kappa B signaling. All these findings indicate that Rnf11-like is an essential component of NF-kappa B signaling pathway for specification of the posterior somites in zebrafish embryos. (C) 2012 Elsevier Inc. All rights reserved.