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

我们正在对兔子免疫系统的基因进行研究，通过 分子生物学技术。我们已经证明了进化 基因片段的序列和连锁关系的保守性 编码T细胞受体β链可变区。三个VBeta基因， 在兔子的单倍体基因组中，每一个都只有一个拷贝 在4290bp的基因组DNA片段上发现。他们似乎没有 经典的上游启动子序列，但这三个序列都表达为 成熟大小的mRNA转录本。连锁兔VBeta显著 彼此不同，更类似于人和小鼠的VBeta 而不是彼此之间。这表明这些基因复制得很早，之前 对兔子和老鼠的辐射。我们发现了限制性片段长度 兔T细胞受体β链常数的RFLP分析 区域基因以及可能的同种异型形式。我们正在使用RFLP 和同种异型来研究兔CBeta和CKappa是否遗传 它们在老鼠身上是相连的，在人类身上是不相连的。一种胚系VBeta基因 与小鼠VBeta 86T1同源，其DNA序列与VBeta 86T1相同 从另一只兔子的cDNAVBeta部分表明 表达的基因没有发生任何体细胞突变。像其他人一样 兔子有两个相似的CBeta基因，但我们现在已经证明 一些兔子似乎有异型CBeta1和三种不同的 卡贝塔。在氨基酸位置上发现了一些CBeta异型。 出现类似的CKappa异型差异的地方。

We are conducting studies of genes of the rabbit immune system by techniques of molecular biology. We have demonstrated evolutionary conservation of both sequence and linkage relationships of gene segments encoding T cell receptor Beta chain variable regions. Three VBeta genes, each represented as only a single copy in the haploid genome of the rabbit was found on a 4,290 bp genomic DNA fragment. They do not appear to have classical upstream promoter sequences but all three are found expressed as mature size mRNA transcripts. The linked rabbit VBeta are remarkably different from each other and are more similar to human and mouse VBeta than to each other. This suggests that the genes duplicated early, prior to rabbit-mouse radiation. We have discovered restriction fragment length polymorphism (RFLP) of the rabbit T cell receptor Beta chain constant region genes as well as probable allotypic forms. We are using the RFLP and allotypes to study whether rabbit CBeta and CKappa are genetically linked as they are in mice, or unlinked as in man. A germline VBeta gene with homology to mouse VBeta 86T1 had a DNA sequence identical to that of the VBeta portion of a cDNA from a second rabbit suggesting that the expressed gene had not undergone any somatic mutations. Like other species, rabbits have two similar CBeta genes but we have now shown that some rabbits appear to have allotypic forms of CBeta1 and three different CBeta. Some CBeta allotypic differences are found at amino acid positions where analogous CKappa allotypic differences occur.