鸡IFITM3基因的序列分析和组织表达特征

Sequence analysis and expression pattern of IFITM3 gene in chicken

目的:探讨干扰素诱导跨膜蛋白3(IFITM3)基因在鸡体内的表达与功能,为IFITM3的深入研究和禽流感的防治提供有价值的参考。方法:本研究通过搜索鸡的基因组数据获得鸡的IFITM3,使用生物信息学分析方法、荧光定量RT-PCR技术对鸡IFITM3基因的遗传进化、蛋白特性和组织表达分布进行了研究。结果:鸡的IFITM3蛋白序列全长113个氨基酸,含有两个长度相似的跨膜区和一个CD225结构域,二级结构与人的IFITM3相似,但N末端差异较大。S-棕榈酰化修饰对于IFITM3的抗病毒活性起着决定性作用。分析显示,鸡的IFITM3共含有4个潜在的S-棕榈酰化位点,即Cys45/49/53/89,意味着鸡的IFITM3蛋白也具有抗病毒活性。荧光定量RT-PCR结果显示,IFITM3在鸡的各组织表达广泛。在检测的17种组织中,仅血液没有表达。另外,IFITM3在以肺、脾为代表的非消化道组织表达量低,在以十二指肠、盲肠为代表的消化道组织和肝脏组织表达量高。鸡的IFITM3与人的IFITM3组织表达特征相似。结论:鸡的IFITM3基因对胃肠道免疫和肝脏免疫有重要作用。

Objective： Investigating the expression and the function of IFITM3 gene of chicken would contribute to further studying for IFITM3,and offer a reference of preventing avian influenza viruses（AIV）.Methods： In this study,the coding sequence of chicken IFITM3 was obtained by searching the chicken genome database.Bioinformatics analysis was used to evaluate the genetic evolution and the specificity of IFITM3 protein.Quantitative RT-PCR was used to evaluate the expression of IFITM3 mRNA in various chicken tissues.Results： Chicken IFITM3 protein is predicted to have 113 amino acids.The structure analyses show that it contains two transmembrane regions and one CD225 domain.The secondary structure of chicken IFITM3 is similar to that of human IFITM3.The difference between chicken and human IFITM3 focuses on the N-terminus.S-palmitoylation modification contribute to the antiviral activity of IFITM3.Our analysis showed that chicken IFITM3 contained 4 potential S-palmitoylation sites（Cys45/49/53/89）,suggesting that it may have anti AIV activity.The expressions of IFITM3 in 17 chicken tissues were detected.The results show that IFITM3 was expressed in all analysed tissues except blood.Quantitative RT-PCR（qRT-PCR） revealed that the relative expression levels of chicken IFITM3 in the digestive tissues and the liver were higher than those in non-digestive tissues,such as lung and spleen.The expression pattern of chicken IFITM3 appears to be similar to that of human IFITM3.Conclusion： These results suggest that chicken IFITM3 gene might play an important role in the immunity of the gastrointestinal tract system and the liver.