Greenberg A S, Avila D, Hughes M, Hughes A, McKinney E C, Flajnik M F
Department of Microbiology and Immunology, University of Miami School of Medicine, Florida 33101.
Nature. 1995 Mar 9;374(6518):168-73. doi: 10.1038/374168a0.
Immunoglobulin and T-cell receptor (TCR) molecules are central to the adaptive immune system. Sequence conservation, similarities in domain structure, and usage of similar recombination signal sequences and recombination machinery indicate that there was probably a time during evolution when an ancestral receptor diverged to the modern-day immunoglobulin and TCR. Other molecules that undergo rearrangement have not been described in vertebrates, nor have intermediates been identified that have features of both these gene families. We report here the isolation of a new member of the immunoglobulin superfamily from the nurse shark, Ginglymostoma cirratum, which contains one variable and five constant domains and is found as a dimer in serum.
免疫球蛋白和T细胞受体（TCR）分子是适应性免疫系统的核心。序列保守性、结构域结构的相似性以及相似重组信号序列和重组机制的使用表明，在进化过程中可能有一段时间，一个祖先受体分化为现代的免疫球蛋白和TCR。在脊椎动物中尚未描述其他经历重排的分子，也未鉴定出具有这两个基因家族特征的中间体。我们在此报告从护士鲨（Ginglymostoma cirratum）中分离出免疫球蛋白超家族的一个新成员，它包含一个可变结构域和五个恒定结构域，并且在血清中以二聚体形式存在。
