Harding F A, Cohen N, Litman G W
Tampa Bay Research Institute, St Petersburg, FL 33716.
Nucleic Acids Res. 1990 Feb 25;18(4):1015-20. doi: 10.1093/nar/18.4.1015.
Immunoglobulin heavy chain genes from Raja erinacea have been isolated by cross hybridization with probes derived from the immunoglobulin genes of Heterodontus francisci (horned shark), a representative of a different elasmobranch order. Heavy chain variable (VH), diversity (DH) and joining (JH) segments are linked closely to constant region (CH) exons, as has been described in another elasmobranch. The nucleotide sequence homology of VH gene segments within Raja and between different elasmobranch species is high, suggesting that members of this phylogenetic subclass may share one VH family. The organization of immunoglobulin genes segments is diverse; both VD-J and VD-DJ joined genes have been detected in the genome of non-lymphoid cells. JH segment sequence diversity is high, in contrast to that seen in a related elasmobranch. These data suggest that the clustered V-D-J-C form of immunoglobulin heavy chain organization, including germline joined components, may occur in all subclasses of elasmobranchs. While variation in VH gene structure is limited, gene organization appears to be diverse.
通过与源自另一种板鳃亚纲目代表物种——宽纹虎鲨（角鲨）免疫球蛋白基因的探针进行交叉杂交，已分离出了猬鳐的免疫球蛋白重链基因。重链可变区（VH）、多样性区（DH）和连接区（JH）片段与恒定区（CH）外显子紧密相连，这与另一种板鳃亚纲动物中的情况一致。猬鳐体内VH基因片段之间以及不同板鳃亚纲物种之间的核苷酸序列同源性很高，这表明该系统发育亚类的成员可能共享一个VH家族。免疫球蛋白基因片段的组织形式多样；在非淋巴细胞基因组中已检测到VD-J和VD-DJ连接基因。与相关板鳃亚纲动物不同，JH片段序列多样性很高。这些数据表明，免疫球蛋白重链组织的V-D-J-C簇状形式，包括种系连接成分，可能存在于所有板鳃亚纲动物亚类中。虽然VH基因结构的变异有限，但基因组织似乎是多样的。
