IG GENETICS--ONTOGENY AND DIFFERENTIATION OF CELLS OF THE RABBIT IMMUNE SYSTEM

IG遗传学--兔免疫系统细胞的个体发育和分化

• 批准号: 3809535
• 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/3809535
• 关键词: B lymphocyte; RNA splicing; T cell receptor; T lymphocyte; cell differentiation; developmental genetics; gene deletion mutation; gene expression; genetic manipulation; genetic regulation; genetic strain; immunoglobulin genes; immunoregulation; laboratory rabbit; leukocyte activation /transformation; messenger RNA; mutant; natural gene amplification; nucleic acid hybridization

We use techniques of classical immunogenetics and of molecular biology to study the genetics of rabbit immunoglobulins (Igs) and T cell receptors (Tcr) and to investigate the regulated expression of Ig and Tcr genes during lymphoid cell development. We have reported that there are evolutionarily conserved IgH enhancer sequences and a donor splice site in the intron between the Ig heavy chain J-region and the IgM heavy chain constant region (C-mu) genes. The presence of the conserved splice site sequences in the JH-C-mu intron region of the human, mouse and rabbit genomes and the utilization of the splice sites to process sterile C-mu mRNA transcripts expressed by developing B cells of mice and rabbits suggests that these transcripts may play a regulatory role during B-cell development. Some rabbits are unusual in having three different copies of Tcr C-beta genes. The third gene is a chimeric C(beta)2-C(beta)1 genomic Tcr beta chain gene that may have arisen by an unequal crossing over event analogous to that which may have deleted C(beta)l, D(beta)2 and J(beta)2 in NZW mice. We demonstrated this in Southern analyses of both total genomic DNA and two different genomic clones of about 6 and about 14 kb as well as by sequencing cloned genomic DNA. Rabbits were bred at the NIH to produce elevated levels of lambda light chains lacking c2l and expressing only c7. These rabbits were shown to produce mRNA and proteins with sequences corresponding to the products of a previously identified genomic lambda light chain gene, C(lambda)6. The production of c2l is known to be due to expression of C(lambda)5. The c2l-negative phenotype reflects deletion of a region including J(lambda)5. The c7-negative phenotype also appears to result from a deletion.

我们使用经典免疫遗传学和分子生物学的技术来 兔免疫球蛋白和T细胞受体的遗传学研究 (TCR)，并研究Ig和TCR基因的调控表达 在淋巴样细胞发育过程中。我们已经报告过，有 进化上保守的IgH增强子序列和供体剪接位点 免疫球蛋白重链J区与免疫球蛋白M重链之间的内含子 恒定区(C-Mu)基因。保守剪接位点的存在 人、小鼠和兔JH-C-MU内含子区域的序列分析 基因组和剪接位点在加工不育C-MU中的利用 小鼠和兔发育中B细胞表达的mRNA转录本 提示这些转录本可能在B细胞过程中发挥调节作用 发展。 有些兔子是不寻常的，因为有三个不同的TCR C-beta副本 基因。第三个基因是嵌合的C(β)2-C(β)1基因组TCRβ 类似事件的不等杂交可能产生的链基因 NZW小鼠中可能缺失C(β)L、D(β)2和J(β)2的基因。 我们在Southern对总基因组DNA和两个 约6kb和约14kb的不同基因组克隆以及 克隆的基因组DNA测序。 在美国国立卫生研究院饲养的兔子产生了高水平的波长光 链缺乏c2L，只表达c7。这些兔子被展示给 产生具有与一种蛋白产物相对应的序列的mRNA和蛋白质 已鉴定的基因组lambda轻链基因C(Lambda)6。 已知C2L的产生是由于C(Lambda)5的表达。 C2L阴性表型反映包括J(Lambda)5在内的一个区域的缺失。 C7阴性表型似乎也是由缺失引起的。