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

兔同种异型——IG 基因的结构、组织和调控表达

• 批准号: 3768753
• 负责人: R G MAGE
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3768753
• 关键词: gene conversion; gene expression; gene mutation; gene rearrangement; genetic polymorphism; gut associated lymphoid tissue; immunoglobulin genes; immunoglobulin structure; laboratory rabbit; nucleic acid sequence; polymerase chain reaction; southern blotting

We study genes of the rabbit immune system by techniques of molecular biology and immunology. Alternative mechanisms such as gene conversion (g.c.) appear to contribute to the diversification of the antibody repertoire in the rabbit. The rabbit appendix develops rapidly between birth and 6 weeks of age, when it seems to reach its maximum size. We analyzed diversification from germline VH gene sequence in individual rabbit appendix follicles. Our results suggest that g.c. is occurring to diversify germline gene sequences in the dark zone cells of the appendix follicles of six week old rabbits. Some changes may have been due to either g.c or somatic hypermutation. Earlier, we found that a relatively small deletion of a segment containing 3' VH genes leads to a mutant phenotype in Alicia (ali) rabbits. We found that the products of the first functional VH gene (VH4a2) or VH4a2-like gene(s) were expressed in two to eight-week-old mutant Alicia; expression of a-negative genes was also elevated but the relative proportions of a-negative decreased as the relative levels of expression of the VH4a2 or VH4a2-like gene(s) increased. The appearance of sequences resembling that of the VH1a2 gene which is deleted in the mutants may be due to g. c. that altered the sequence of the rearranged VH4a2; rearrangement of upstream VH1a2-like genes may also occur later in development. We described the rabbit RAG locus and genomic and expressed RAG-1 and RAG-2 genes. Genetic polymorphism of the rabbit RAG-2 gene was observed by sequencing and Southern analyses. Expressed RAG-2 cDNAs with different sequences were both functional in a recombinase assay. RAG-1 and RAG-2 positive cells can be found in the 6 week normal rabbit appendix. Scattered throughout the M cells pockets, the corona, and both the dark and light zones of germinal centers. PCR allows us to specifically identify excision circles resulting from VL to JL DNA rearrangements. Circular products reflecting VLJL rearrangements were detected in the appendix of two week-old and adult animals.

我们用分子生物学技术研究了兔免疫系统的基因， 生物学和免疫学。 替代机制，如基因转换 （g.c.）似乎有助于抗体的多样化 在兔子的记忆中 兔子的阑尾在 出生和6周龄，当它似乎达到其最大尺寸。我们 分析了个体中来自生殖系VH基因序列的多样性 家兔阑尾滤泡。 我们的研究结果表明，g.c.发生在 使阑尾暗区细胞的生殖系基因序列多样化 6周龄兔子的卵泡。 一些变化可能是由于 要么是基因突变要么是体细胞超变 早些时候，我们发现， 含有3 ′ VH基因的区段的小缺失导致突变体 Alicia（ali）兔的表型。 我们发现， 第一个功能性VH基因（VH 4a 2）或VH 4a 2样基因表达于 两到八周龄的突变体艾丽西亚; a-阴性基因的表达是 也升高，但a-阴性的相对比例下降， VH 4a 2或VH 4a 2样基因的相对表达水平 增加 出现类似于VH 1a 2基因的序列 在突变体中缺失的可能是由于g. C.改变了 上游VH 1a 2样重排 基因也可能在发育后期出现。 我们描述了兔子RAG RAG-1和RAG-2基因的表达。 遗传 通过序列测定， 南方分析 表达的不同序列的RAG-2 cDNA， 两者都在重组酶测定中起作用。 RAG-1和RAG-2阳性细胞 在6周龄正常家兔阑尾中可见。分散在 M细胞袋，冠，以及暗区和亮区， 老年中心 PCR使我们能够特异性地识别切除环 由VL至JL DNA重排引起。 圆形产品反映 VLJL重排在2周龄的鸡阑尾中检测到， 成年动物