Gene structure and transcription of IRF-2 in the mandarin fish Siniperca chuatsi with the finding of alternative transcripts and microsatellite in the coding region

Abstract

The gene of interferon regulatory factor-2 (IRF-2) has been cloned from the mandarin fish (Siniperca chuatsi). The IRF-2 gene has 6,418 nucleotides (nt) and contains eight exons and seven introns, encoding two mRNAs. The two IRF-2 mRNAs each contained an open reading frame of 873 nt, which both translate into the same 291 amino acids but differed in their 5′ untranslated region: one mRNA was transcribed initially from the exon 1 bypassing exon 2, while the other was transcribed from the exon 2. The microsatellites (CA repeats) could be found in the carboxyl terminal region of mandarin fish IRF-2, which result in the truncated form molecules. The microsatellites' polymorphism was investigated, and eight alleles were found in 16 individuals. The microsatellites were also examined in IRF-2 of several freshwater perciform fishes. The transcription of the IRF-2 in different tissues with or without poly inosine-cytidine stimulation was analyzed by real-time PCR, and the constitutive transcription of both molecules could be detected in all the tissues examined.

Interferon regulatory factor-2 in orange-spotted grouper (Epinephelus coioides): Gene, inductive expression pattern and subcellular localization

“…When injected with polyI:C or LPS, the increased expression is in immune-related tissues, especially in head kidney. These results are consistent with other fish IRF-2 gene expression patterns, such as mandarin fish and snakehead fish (Sun et al, 2006;Jia and Guo, 2008). However, in the gill, the EcIRF-2 gene has a low expression level compared to those fish, and the decreased expression following stimulation of polyI:C or LPS appeared in both orange-spotted grouper and mandarin fish.…”

“…IRF-2 also has an unexpected role in the regulation of apoptosis and cell growth (Cuesta et al, 2003). Due to the significant differences between mammals and fish, much effort has been made to study fish IRF family in recent years, and a few members have been reported, such as IRF-1, IRF-2, IRF-3 and IRF-7 (Holland et al, 2008;Kileng et al, 2009;Caipang et al, 2009;Jia and Guo, 2008;Sun et al, 2006;Collet et al, 2003;Zhang et al, 2003).…”

Gene structures and promoter characteristics of interferon regulatory factor 1 (IRF-1), IRF-2 and IRF-7 from snakehead Channa argus

“…At present, fish IRF-1, IRF-2 and IRF-7 genes are shown to be induced by virus, IFN or poly I:C in several species (Collet et al, 2003a,b;Ordas et al, 2006;Sun et al, 2006Sun et al, , 2007Zhang et al, 2003). Our findings also indicated that poly I:C can induce the expression of CaIRF genes in snakehead spleen and liver.…”

“…Among teleost IRFs, IRF-1 has been cloned and characterized from flounder (Paralichthys olicaceus), pufferfish (Fugu rubripes), rainbow trout (Oncorhynchus mykiss), turbot (Scophthamus maximus) and sea bream (Sparus aurata) (Yabu et al, 1998;Richardson et al, 2001;Collet et al, 2003a,b;Ordas et al, 2006). IRF-2 has been reported in rainbow trout and mandarin fish (Siniperca chuatsi), and homologous to known vertebrate IRF-2 (Collet et al, 2003a,b;Sun et al, 2006). Moreover, IRF-7 has been cloned from goldfish (Carassius auratus) and mandarin fish (Zhang et al, 2003;Sun et al, 2007).…”

“…The functional studies of fish IRFs showed that they have characteristic properties of mammalian IRFs. IRF-1 gene was induced by virus in flounder and poly I:C in trout, turbot, sea bream (Collet et al, 2003a,b;Ordas et al, 2006), and IRF-2 gene was induced by poly I:C in trout and mandarin fish (Collet et al, 2003a,b;Sun et al, 2006). The IRF-7 gene was up-regulated by virus-infection or IFN treatment in goldfish, and induced by poly I:C in mandarin fish (Zhang et al, 2003;Sun et al, 2007).…”