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

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。我们生产了抗RAG-2抗体，并研究了 发育兔胸腺和阑尾组织。我们使用了表面 CD43和IgM标记物用于鉴别两种阑尾细胞群 6-9周龄表达RAG-1转录本的兔。我们推测 CD43在B细胞成熟不同阶段的表达 可能与阑尾的功能有关，既是B细胞的一个部位 发展和多样化。IgM相关B细胞受体 在兔B细胞上发现了以异构体结构存在的分子 合成了约75 kDa和135 kDa的未还原分子量 由37和42 kDa亚基组成。用单抗进行免疫学研究 抗体提示这些蛋白是兔的同源蛋白。 小鼠Ig-β(B29)和Ig-α(mb-1)。我们调查了RAD51在 兔阑尾，因为我们推测RAD51可能在 发生在幼兔阑尾的基因转换事件以实现多样化 他们的抗体库。克隆并测序RT-PCR扩增产物 兔RAD51的编码序列，发现兔、人和 鼠标RAD51高度相似。我们开发了一种逆转录酶聚合酶链式反应 模拟实验和测定RAD51转录本的相对丰度 不同的组织，在FACS中分类B细胞和T细胞以及B细胞亚群。我们 在睾丸、胸腺和胸腺中发现较高水平的RAD51信息 可能与高有丝分裂和/或减数分裂活动相关的附件。 在Northern blotts上发现的三种不同大小的条带可能反映了 不同的转录起始点、选择性剪接或 不同的聚(A)加成部位。在人和老鼠中，3‘-最大的DH 基因DQ52在B细胞发育早期优先重排。 为了测试这种对重排DH基因片段的偏好是否基于 在兔的3‘端存在邻近，我们克隆并测序了该兔 DQ52基因。编码区序列与鼠标DQ52相同，但 3‘重组信号序列具有非典型的非异构体。DQ52 基因被利用的频率非常低，如果有的话。我们只找到了一个VDJ 从28天的胎肝B细胞中提取的8个碱基的序列与 胚系DQ52序列。而不是重新排列另一种水解酶基因DQ52， 位于JH上游约32kb的Df是首选靶标。 因此，与人和小鼠相比，兔子优先表达水解酶 该基因位于B细胞个体发育早期的水解区中部。 这可能与VH到DH的初始重排更频繁有关 在兔B细胞中。

We studied genes of the rabbit immune system by techniques of molecular biology and immunology. We produced anti-RAG-2 antibodies and studied developing rabbit thymus and appendix tissues. We used the surface markers CD43 and IgM to distinguish two appendix cell populations from 6 to 9-week-old rabbits that expressed RAG-1 transcripts. We speculate that the appearance of CD43 during different stages of B-cell maturation may be related to the function of the appendix as a site of both B-cell development and diversification. IgM associated B cell receptor molecules were found on rabbit B cells as heteromeric structures with nonreduced molecular weights of approximately 75 kDa and 135 kDa composed of 37 and 42 kDa subunits. Immunological studies with monoclonal antibodies suggested that these proteins are the rabbit homologues of murine Ig-beta (B29) and Ig-alpha (mb-1). We investigated RAD51 in rabbit appendix because we postulated that RAD51 could play a role in the gene conversion events that occur in young rabbit appendix to diversify their antibody repertoire. We cloned and sequenced RT-PCR amplified rabbit RAD51 and found that the coding sequences of rabbit, human and mouse RAD51 are highly similar. We developed a reverse transcriptase PCR mimic assay and measured the relative abundance of RAD51 transcripts in different tissues, in FACS-sorted B and T cells and B-cell subsets. We found relatively high levels of RAD51 message in testis, thymus and appendix that may correlate with high mitotic and/or meiotic activities. Bands of three different sizes found on Northern blots could reflect distinct transcription initiation sites, alternative splicing or different poly (A) addition sites. In man and mouse, the 3'-most DH gene, DQ52, is preferentially rearranged early in B-cell development. To test whether this preference for rearranging a DH gene segment based on 3' end proximity exists in rabbit, we cloned and sequenced the rabbit DQ52 gene. The coding region sequence is identical to a mouse DQ52 but the 3' recombination signal sequence has an atypical nonamer. The DQ52 gene was utilized very infrequently, if at all. We found only one VDJ sequence from 28 day fetal liver B-cells with 8 bp that matched the germline DQ52 sequence. Instead of rearranging DQ52, another DH gene, Df, localized about 32 kb upstream of the JH was the preferred target. Thus, in contrast to man and mouse, rabbits preferentially express a DH gene located in the middle of the DH region early in B cell ontogeny. This may correlate with more frequent initial rearrangement of VH to DH in rabbit B cells.