REARRANGEMENT AND REGULATION OF IMMUNOGLOBULIN GENES

编码免疫球蛋白的基因片段具有仅 在它们经历特定的遗传过程后， 在发育中的B淋巴细胞中的重排。 为了解 调节抗体产生的复杂控制， 研究基因片段重排的机制， 调节其转录的元件。 抗体的形成 基因需要DNA的位点特异性易位， 轻链将数百个可变片段之一变成四个可变片段之一 连接位于恒定片段上游约3 kb的片段。 两 重组Kappa基因座的功能和非功能片段， 浆细胞瘤，以及相互的碎片，这是由产生的 重排，将通过DNA测序表征，并与 确定Kappa重排和结构 转录的要求。 Kappa的染色体定位 重排和非Kappa DNA片段的起源， 将确定Kappa基因座。 重排的系统分析 将在克隆衍生的淋巴样细胞系中进行， 文化中的Kappa基因座。 这些因素有助于 转录效率将通过分析 异常重排的转录能力， Kappa转录单位的突变或缺失。 研究将 开始识别DNA的特定区域， 通过在SV 40中瞬时表达κ基因的体内转录 载体-HeLa细胞系统。 转录研究的最终目标是 确定影响DNA与元素相互作用的结构 对于细胞系中的转录调节是重要的， 刺激或抑制抗体产生。

The gene segments encoding immunoglobulins have the novel property of only being functionally expressed after they undergo specific genetic rearrangements in the developing B lymphocyte. In order to understand the complex controls which regulate antibody production it is necessary to examine the mechanisms by which the gene segments are rearranged and the elements which regulate their transcription. The formation of antibody genes requires site specific translocations of DNA, which for mouse Kappa light chains brings one of several hundred variable segments to one of four joining segments located about 3 kb upstream of a constant segment. Both functional and nonfunctional fragments of the rearranged Kappa locus in plasmacytomas, as well as reciprocal fragments which are generated by the rearrangement, will be characterized by DNA sequencing and compared to determine the consequence of Kappa rearrangements and structural requirements for transcription. The chromosomal location of Kappa rearrangements and origins of non Kappa DNA segments which rearrange into the Kappa locus will be determined. A systematic analysis of rearrangement will be followed in a clonally derived lymphoid cell line which rearranges the Kappa locus in culture. The elements which contribute to transcriptional efficiency will be determined by analyzing the transcriptional competence of aberrant rearrangements which represent mutations or deletions of the Kappa transcription unit. Studies will be initiated to identify specific regions of the DNA required for transcription in vivo by transient expression of Kappa genes in an SV40 vector-HeLa cell system. The ultimate goal of transcription studies will be to determine structures which affect interactions of DNA with elements important for transcriptional regulation in cell lines which can be stimulated or suppressed for antibody production.