RABBIT ALLOTYPES--STRUCTURE, ORGANIZATION AND REGULATED EXPRESSION OF IG GENES

我们用分子生物学技术研究了兔免疫系统的基因， 生物学结合免疫学测定。艾丽西亚系家兔 具有与免疫球蛋白重链分离的突变（ali） (Igh）基因座，并对重链的表达具有顺式效应 编码α 2同种异型的可变区基因（VH）。我们一直在繁殖 这些动物在国家卫生研究院来自纯合突变体和野生型的基因组DNA 使用各种不同的Southern分析， 限制性内切酶和IgH探针。然而，在DNA的研究中， 用不常使用的切割酶分离的昆虫片段， 横向交变场电泳，我们发现了一个相对较小的 缺失含有具有重要调节作用的3' VH基因的区段 功能，其丧失导致ALI表型。我们对VH的研究 B细胞中的基因重排提示VH基因座的3'末端 可能在调节兔VH基因表达中起关键作用 因为该区域中的VH基因是优先VDJ的靶标 重新安排这就提出了替代机制 类似的基因转换在工作中产生抗体库， 这个物种。 我们目前正在研究免疫球蛋白重链之间的五种重组体 链可变区（VH）和恒定区（CH）基因。两个VH-CH 在我们的实验室发现了重组体，在巴塞尔发现了三个重组体。 免疫学研究所。为了使网站本地化， 重组，导致新的单倍型，我们一直在分析DNA 从亲本和重组单倍型使用一组探针跨越 Igh基因座的VH、DH、JH、C（mu）和C（gamma）区。所有五 重组位点位于整个VH基因簇的下游;三个重组位点位于整个VH基因簇的下游。 似乎发生在含有DH基因的区域内， C（mu）的下游。 兔κ轻链恒定区基因有两个拷贝 区域，（kappa）1和（kappa）2。我们现在已经证明，这些基因 每一个都有相关的V（kappa）和J（kappa）基因。 我们已经获得了分离的和纯的B细胞群， λ或κ 2轻链，并显示（κ）1基因已被 从许多表达λ轻链的B细胞中缺失。

We study genes of the rabbit immune system by techniques of molecular biology coupled with immunological assays. Rabbits of the Alicia strain have a mutation (ali) that segregates with the immunoglobulin heavy chain (Igh ) locus and has a cis effect upon the expression of heavy chain variable region genes (VH) encoding the a2 allotype. We have been breeding these animals at the NIH. Genomic DNAs from homozygous mutant and wild type animals were indistinguishable by Southern analyses using a variety of restriction enzyme digests and Igh probes. However, in studies of DNA fragments from digests with infrequently cutting enzymes separated by transverse alternating field electrophoresis, we found a relatively small deletion of a segment containing 3' VH genes with important regulatory functions, the loss of which leads to the ali phenotype. Our studies of VH gene rearrangement in B-cells suggest that the 3' end of the VH locus probably plays a key role in regulation of VH gene expression in rabbits because VH gene(s) in this region are the targets of preferential VDJ rearrangements. This raises the possibility that alternative mechanisms like gene conversion are at work to generate the antibody repertoire in this species. We are currently studying five recombinants between immunoglobulin heavy chain variable region (VH) and constant region (CH) genes. Two of the VH-CH recombinants were discovered in our laboratory and three at the Basel Institute for Immunology. In order to localize the sites of the recombinations that led to the new haplotypes, we have been analyzing DNAs from the parental and recombinant haplotypes using a set of probes spanning the VH, DH, JH, C(mu) and C(gamma) regions of the Igh locus. All five recombination sites were downstream of the entire VH gene cluster; three appear to have occurred within the region containing DH genes and one downstream of C(mu). There are two copies of the gene for the rabbit kappa light chain constant region, (kappa)1 and (kappa)2. We have now shown that these genes are more than 1 Mb apart and each has associated V(kappa) as well as J(kappa) genes. We have obtained separated and pure populations of B cells expressing lambda or kappa 2 light chains and shown that the (kappa)1 gene has been deleted from many of the B cells expressing lambda light chains.