Sheehan K M, Brodeur P H
Immunology Program, Sackler School of Graduate Biomedical Sciences, Boston, MA.
EMBO J. 1989 Aug;8(8):2313-20. doi: 10.1002/j.1460-2075.1989.tb08358.x.
The generation of the primary antibody repertoire requires the somatic rearrangement of germline gene segments. It is not known, however, whether all functional V and J gene segments have an equal probability of contributing to this initial set of antibody specificities. To address this issue, we have examined the relative utilization of VH and JH gene segments of the mouse. We have constructed VH cDNA phage libraries from C mu transcripts obtained from polyclonally activated spleen cells of the BALB/c and C57BL/6 strains. We show that probes specific for either one, two or three functional VH gene segments hybridize to cDNAs at frequencies directly proportional to the number of functional germline VH genes detected by each probe. In contrast, the representation of 10 VH gene families within each library indicates that certain families are under-represented relative to their estimated germline gene number. These families must either have extraordinary proportions of nonfunctional genes or are influenced by as yet unidentified regulatory mechanisms or constraints on rearrangement.
初级抗体库的产生需要种系基因片段的体细胞重排。然而，尚不清楚所有功能性V基因片段和J基因片段对这组初始抗体特异性的贡献概率是否相同。为了解决这个问题，我们研究了小鼠VH和JH基因片段的相对利用率。我们从BALB/c和C57BL/6品系多克隆激活的脾细胞中获得的Cμ转录本构建了VH cDNA噬菌体文库。我们发现，针对一个、两个或三个功能性VH基因片段的特异性探针与cDNA杂交的频率与每个探针检测到的功能性种系VH基因数量成正比。相比之下，每个文库中10个VH基因家族的表现表明，某些家族相对于其估计的种系基因数量而言代表性不足。这些家族要么具有极高比例的非功能性基因，要么受到尚未确定的调控机制或重排限制的影响。
