Molecular Cloning and Functional Analysis of IRF-1 in the Asian Swamp Eel (Monopterus albus)

Özet

Interferon regulatory factors (IRFs) have been studied in mammals and various fish species, but not in the Asian swampeel (Monopterus albus). Complete IRF-1 cDNA sequence and genomic DNA sequence of M. albus were cloned. The IRF-1gene, named maIRF1, spanned 3.5 kb from the transcription start site to the polyadenylation signal. The maIRF mRNAcontained an open reading frame of 885 nucleotides, which translated into 294 amino acids. The overall amino acid cDNAsequences shared 42.5-81.0% identity with IRF-1 in Mandarin (Siniperca chuatsi), Crucian carp (Carassius auratus), Atlanticsalmon (Salmo salar), Grass carp (Ctenopharyngodon idella), Zebrafish (Danio rerio) and Fugu (Takifugu rubripes), and36.6-38.0% identity with IRF-1 in Chicken (Gallus gallus), Frog (Xenopus tropicalis), Human (Homo sapiens) and Mouse(Mus musculus). Quantitative real-time PCR revealed that maIRF1 expression changed little during the three different growthstages (female, intersex, male). Moreover, maIRF was constitutively expressed in all analyzed organs, being mostpredominantly expressed in the trunk kidneys and blood and the least in muscle tissue. The expression levels of maIRF1 weretested in trunk kidney and spleen after challenge with synthetic double-stranded RNA poly I:C and lipopolysaccharide (LPS).It was found that maIRF1 expression changed significantly 24-72 h after injection (P<0.05), which demonstrated that maIRF1plays an important role in congenital immunity and adaptive immunity of M. albus.