The Evolution of Lymphocyte Recognition

这项研究的长期目标是了解 免疫球蛋白（IG）结构、组织和表达 金鱼的重链基因。 基因组 已在λ噬菌体中构建文库;初始测序 三个VH相关基因的研究已经完成， 通过寡核苷酸探针鉴定了区域 杂交方法 这些研究将在三个领域扩大。 首先，代表性的VH、DH、JH和CH区域将被标记。 鉴定并测序以阐明它们的种系 organization. 标准DNA克隆、作图和测序 战略将被使用。 为了鉴定CH区， 金鱼IgM重链将进行微测序， 将合成混合的寡核苷酸探针以对应于 它们的编码序列 第二，计算机辅助分析 金鱼VH基因序列和比较这些与每个 其它的和与其它脊椎动物的公开的VH序列一起， 试图推断出相对贡献 选择，突变，漂移，和非互惠交换， 这些基因的进化。 三、推定的功能 金鱼IG重链基因的调控区将被 研究了 将构建适当的表达载体， 测试金鱼重链启动子（联合 具有哺乳动物IG增强子区）允许基因表达， 哺乳动物淋巴样细胞 动物免疫功能的机制， 对哺乳动物的了解还很少。 基础知识 表达的结构、组织和调节 鱼类免疫球蛋白基因重要性不仅在于 内在的兴趣，也是因为对免疫的理解 在鱼类中的功能是生长能力的基础， 在商业养殖中维持鱼类，并了解 鱼类在海洋中生存成败的因素 自然环境。 免疫进化的知识 从这些研究中获得的函数也可以揭示 高等脊椎动物免疫系统的功能。

The long term goals of this research are to understand the structure, organization, and expression of immunoglobulin (Ig) heavy chain genes in the goldfish, Carassius auratus. A genomic library has been constructed in lambda phage; initial sequencing of three VH.related genes has been completed, and putative JH regions have been identified by oligonucleotide probe hybridization. These studies will be expanded in three areas. First, representative VH, DH, JH, and CH regions will be identified and sequenced to elucidate their germline organization. Standard DNA cloning, mapping, and sequencing strategies will be used. To identify CH regions, peptides of goldfish IgM heavy chains will be microsequenced, and specific mixed oligonucleotide probes will be synthesized to correspond to their coding sequences. Second, computer assisted analyses of goldfish VH gene sequences and comparison of these with each other and with published VH sequences for other vertebrates will be undertaken in an attempt to infer the relative contributions of selection, mutation, drift, and non.reciprocal exchange in the evolution of these genes. Third, the function of putative regulatory regions of the goldfish Ig heavy chain genes will be studied. Appropriate expression vectors will be constructed to test whether the goldfish heavy chain promoter (in association with a mammalian Ig enhancer region) permits gene expression in mammalian lymphoid cells. The mechanisms of immune function in animals other than mammals are as yet poorly understood. Basic knowledge of the structure, organization and regulation of expression of immunoglobulin genes in fish is of importance not only for its intrinsic interest, but also because understanding of immune function in fish is fundamental for the capability to grow and maintain of fish in commercial culture and for understanding the factors involved in the success or failure of fish to survive in natural environments. Knowledge of the evolution of immune function obtained from these studies may also shed light on the function of immune systems in higher vertebrates.