鲫鱼免疫球蛋白基因的鉴定、应答和功能研究

发布时间：2018-04-27 14:33

  本文选题：免疫球蛋白基因 + 分离鉴定　； 参考：《浙江大学》2008年博士论文

【摘要】： 本研究在鲫鱼中分离鉴定了5类免疫球蛋白基因,包括IgM基因、IgZ基因和嵌合型的IgMZ1、IgMZ2及IgZ2基因。除了IgZ2基因只分离出分泌型外,其他基因都具有分泌型和膜型两种存在形式。对这些基因序列和分子结构进行系统分析后发现鲫鱼IgZ基因也具有与斑马鱼IgZ类似的结构特点,不同的是,鲫鱼IgZ还能以“分子间”嵌合(IgMZ1和IgMZ2)和“分子内”嵌合(IgZ2)的形式存在;同时在IgM分子中还可能存在类铰链区和补体位点。进一步对嵌合基因形成机制进行研究,发现IgZ类嵌合基因的形成可能发生在DNA水平。 IgZ作为一类在硬骨鱼中新发现的抗体类型,其应答方式还未有深入研究。因此,本研究选取典型的胸腺依赖性抗原BSA和胸腺非依赖型抗原LPS以及致病菌嗜水性气单胞菌(Aeromonas hydrophila)免疫鲫鱼,分别研究了IgM、IgZ和IgMZ1在不同刺激条件下脾脏、头肾和外周血中的基因表达变化及在血清、体表和肠道的应答规律。结果显示IgMZ和IgZ主要在体表和肠道等黏膜系统发挥免疫作用,而IgM则在不同器官和组织中都广泛存在,尤其在血清中是主要的抗体类型。 本研究还首次在鲫鱼外周血中鉴定出IgM~+、IgZ~+和IgM~+/IgZ~+等不同标记的B淋巴细胞。进一步的研究发现淋巴细胞表面的IgM可能与淋巴细胞的吞噬作用有关,而IgZ则不然,表明不同标记的淋巴细胞可能具有不同的功能。 结合以上的研究结果,本研究还对鲫鱼等硬骨鱼类及其他物种中的免疫球蛋白基因进行了进化分析,发现硬骨鱼IgZ类基因可能与哺乳动物IgA有一定的进化关系,并提出了免疫球蛋白基因起源与进化的假说。
[Abstract]:In this study, five kinds of immunoglobulin genes were isolated and identified from crucian carp, including IgM gene, IgM gene, chimeric IgMZ1, IgMZ2 and IgZ2 genes. Except for the secretory type isolated from IgZ2 gene, the other genes have two forms: secretory type and membranous type. After systematic analysis of the sequence and molecular structure of these genes, it was found that the IgZ gene of crucian carp also had structural characteristics similar to that of zebrafish IgZ. Carassius auratus IgZ can also exist in the form of "intermolecular" chimeric IgMZ1 and IgMZ2) and "intramolecular" chimeric IgZ2), at the same time, there may be hinge like region and complement site in IgM molecule. The mechanism of chimeric gene formation was further studied. It was found that the formation of chimerism gene of IgZ might occur at DNA level. As a new type of antibody found in bony fish, IgZ response has not been further studied. Therefore, the typical thymus dependent antigens (BSA) and thymus independent antigens (LPS) and pathogenic bacteria Aeromonas hydrophila (Aeromonas hydrophila) were selected to immunize crucian carp. Changes of gene expression in head kidney and peripheral blood and its response in serum, body surface and intestine. The results showed that IgMZ and IgZ mainly played an immune role in the mucosal system such as body surface and intestinal tract, while IgM existed widely in different organs and tissues, especially in serum, which was the main antibody type. In this study, the B lymphocytes labeled with IgM ~ + and IgM ~ / / IgZ ~ ~ were identified for the first time in the peripheral blood of Carassius auratus. Further studies showed that IgM on the surface of lymphocytes may be related to the phagocytosis of lymphocytes, but not IgZ, suggesting that different labeled lymphocytes may have different functions. Based on the above results, the immunoglobulin genes in crucian carp and other species were analyzed. It was found that the IgZ gene of bony fish may have a certain evolutionary relationship with mammalian IgA. The hypothesis of the origin and evolution of immunoglobulin gene was put forward.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：R392

【引证文献】

相关博士学位论文 前1条

1 李春涛;黄颡鱼IgM分子及其表达研究[D];西南大学;2012年

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