Ficolin在毛蚶抗弧菌感染中的作用  

Immune role of Ficolin in Scapharca subcrenata against Vibrio infection

作　　者：冯泽斌 王进京 范家伟 刘桂龙 徐鑫 许贺 王春德 宁军号 卢霞 FENG Zebin;WANG Jinjing;FAN Jiawei;LIU Guilong;XU Xin;XU He;WANG Chunde;NING Junhao;Lu Xia(College of Life Sciences,Yantai University,Yantai 264006 China;Yantai Institute of Coastal Zone,Chinese Academy of Sciences,Yantai 264003,China;Yantai Spring-Sea Aquaseed Co.,Ltd.,Yantai 264006,China;Jiangsu Baoyuan Biotechnology Co.,Ltd.,Lianyungang 222144,China;Jiangsu Haitai Marine Technology Co.,Ltd.,Lianyungang 222144,China)

机构地区：[1]烟台大学生命科学学院,山东烟台264006 [2]中国科学院烟台海岸带研究所,山东烟台264003 [3]烟台海之春水产种业有限公司,山东烟台264006 [4]江苏宝源生物科技有限公司,江苏连云港222144 [5]江苏海泰海洋科技有限公司,江苏连云港222144

出　　处：《海洋科学》2024年第2期43-57,共15页Marine Sciences

基　　金：山东省重点研发计划(农业良种工程)项目(2023LZGCQY006);2022年烟台市水产种业提升项目。

摘　　要：Ficolin是一类含FBG结构域的蛋白,在动物免疫防御中发挥重要作用。无脊椎动物中,Ficolin主要作为模式识别受体和免疫效应分子发挥免疫功能。本研究从毛蚶中克隆获得一条Ficolin基因(命名为SsFic1),该基因编码区序列长度为897 bp,编码298个氨基酸,推测的蛋白含有典型的FBG结构域和Coiled coil结构域,但未发现胶原样结构域。SsFic1的mRNA在毛蚶各组织中广泛分布,其中在肝胰腺和鳃中表达丰度较高,但SsFic1转录产物在卵细胞和四细胞期未检测到,说明该基因不是母源性免疫基因。副溶血弧菌和脂多糖、葡聚糖等免疫刺激物均可诱导SsFic1显著上调表达。利用RNAi技术抑制SsFic1基因表达,酚氧化酶激活因子PAF和补体相关基因(C1qDC、补体C3和Fic3)的表达量及CAT、SOD和PO的酶活力均显著下降,而TEP、C1q2和Fic2等基因的表达显著上调。敲降SsFic1表达后,感染副溶血弧菌后毛蚶血细胞数量和吞噬能力均显著低于对照组,这也是RNAi实验组毛蚶死亡率和血细胞凋亡率显著升高的原因。综上,SsFic1可能通过调控补体通路和酚氧化酶原激活通路参与毛蚶免疫防御反应,这对贝类免疫学研究及抗病新品系的选育具有重要意义。The FBG-domain constituting proteins(ficolins)play significant roles in immune defense in animals.In invertebrates,ficolins act as pattern recognition receptors and immune effectors in immune defense.In this study,a ficolin gene(designed as SsFic1)was cloned from the ark shell Scapharca subcrenata.The coding sequence of SsFic1 was 897 bp,encoding a peptide of 298 amino acids containing a typical FBG domain and coiled domain but lacking a collagen-like domain.SsFic1 mRNA was widely distributed in all tested tissues,with high relative expression levels in the hepatopancreas and gills.The transcripts of SsFic1 were not detected in fertilized eggs or four-cell embryos,suggesting that it is not a maternal immune gene.SsFic1 expression could be induced at high levels by Vibrio parahaemolyticus,LPS,and Glu.Knockdown of SsFic1 by RNAi significantly inhibited the expression of PAF,C1qDC,complement C3,SsFic3,and the enzyme activities of CAT,SOD,and PO,while the expression of TEP,C1q2,and SsFic2 was upregulated.In addition,knocking down SsFic1 reduced the total number and phagocytosis rate of hemocytes when ark shells were challenged by V.parahaemolyticus,resulting in a lower survival rate and higher cell apoptotic levels in ark shells.In summary,SsFic1 may play crucial roles in immune defense against pathogen infection in ark shells by regulating the complement and proPO activating pathways,which is conducive to the immunology of shellfish and the breeding of disease-resistant strains.

关 键 词：毛蚶 FICOLIN 表达模式 RNA干扰 免疫防御 

分 类 号：S917[农业科学—水产科学]