Characterization of the interleukin 1 receptor-associated kinase 4 (IRAK4)-encoding gene in salmonid fish: The functional copy is rearranged in Oncorhynchus mykiss and that factor can impair TLR signaling in mammalian cells

Insights into molecular profiles and genomic evolution of an IRAK4 homolog from rock bream (Oplegnathus fasciatus): Immunogen- and pathogen-induced transcriptional expression

“…Despite of the studies reporting the identification of IRAK4 gene, information regarding the genomic arrangement is rather limited [19]. In the current study, we determined that OfIRAK4 is structured with eleven exons and ten introns.…”

“…In addition, certain exons were group specifically equal in length (E8/E9, 187/184 and E10/E11, 165/159 in teleost and tetrapod lineages, respectively). According to a recent report, IRAK4 of some salmonid species, such as rainbow trout and whitefish has been subjected to rearrangement through an exonfusion event (Table 2A) [19].…”

“…In consistent with this hypothesis, our data implicate that IRAK4 gene could have accumulated introns throughout the evolution, which allowed the higher-order vertebrate IRAK4s to be alternatively spliced. For instance, a pseudogene of trout termed IRAK4s was suspected to be the spliced copy of trout IRAK4 gene and it was suggested that they originated from a recent gene duplication event [19].…”

“…A few invertebrate IRAK4 homologs have been identified, including those from Euprymna scolopes [12], Suberites domuncula [13], Mya arenaria [14], Haliotis diversicolor [15], and their mRNA expression has been investigated in healthy tissues and postpathogen infection. To the best of our knowledge, a few teleostean IRAK4 homologs have also been reported from Danio rerio [16], Cynoglossus semilaevis [17], Trachidermus fasciatus [18] and three salmonids [19]. However, these studies have not provided an insight into the exon-intron structure (except the recently published data in salmonids [19]), and genomic evolution of IRAK4 in teleost with respect to other lineages.…”

“…To the best of our knowledge, a few teleostean IRAK4 homologs have also been reported from Danio rerio [16], Cynoglossus semilaevis [17], Trachidermus fasciatus [18] and three salmonids [19]. However, these studies have not provided an insight into the exon-intron structure (except the recently published data in salmonids [19]), and genomic evolution of IRAK4 in teleost with respect to other lineages.…”