Gene cloning and induced expression pattern of IRF4 and IRF10 in the Asian swamp eel(Monopterus albus)

The Asian swamp eel(Monopterus albus) is one of the most economically important freshwater fish in East Asia,but data on the immune genes of M.albus are scarce compared to other commercially important fish.A better understanding of the eel's immune responses may help in developing strategies for disease management,potentially improving yields and mitigating losses.In mammals,interferon regulatory factors(IRFs) play a vital role in both the innate and adaptive immune system; though among teleosts IRF4 and IRF10 have seldom been studied.In this study,we characterized IRF4 and IRF10 from M.albus(maIRF4 and maIRF10) and found that maIRF4 cDNA consists of 1 716 nucleotides encoding a 451 amino acid(aa) protein,while maIRF10 consists of 1 744 nucleotides including an open reading frame(ORF) of 1 236 nt encoding 411 aa.The maIRF10 gene was constitutively expressed at high levels in a variety of tissues,while maIRF4 showed a very limited expression pattern.Expression of maIRF4 and maIRF10 in head kidney,and spleen tissues was significantly up-regulated from 12 h to 48 h post-stimulation with polyinosinic: polycytidylic acid(poly I:C),lipopolysaccharide(LPS) and a common pathogenic bacteria Aeromonas hydrophila.These results suggest that IRF4 and IRF10 play roles in immune responses to both viral and bacterial infections in M.albus.

硬骨鱼类干扰素调节因子4,8,9,10基因比较

目的：为了阐明硬骨鱼类IRF4、IRF8、IRF0和IRF10在进化上的保守及分化。方法：从Ensembl和NCBI数据库下载基因的DNA和蛋白序列，绘制基因框架图，利用Mega5．0构建系统进化树，采用DNAStar计算蛋白相似率，利用Pfam软件分析保守结构域。结果：IRF8和IRFIO是相当保守的。各种硬骨鱼类中IRF8和IRF10基本一致。不同物种IRF8蛋白相似性最高（60％-87％），其次为IRF10（49～78％）。但IRF9和IRF4分化较大。硬骨鱼类有1—2个IRF9基因，1—3个IRF4基因。不同物种IRF4蛋白相似率为54—88％，IRF0更低（35—71％）。此外，在硬骨鱼类IRF9和IRF4蛋白上还发现有多种结构域。结论：硬骨鱼类IRF8和IRFIO非常保守，不同物种均含有8个外显子和7个内含子，蛋白相似性分别达到60％-87％和49。78％。IRF4和IRF0分化更大，不同物种基因数量从1变化到3，蛋白相似率低。