Restriction fragment length polymorphisms and single germline coding region sequence in VH18/2, a duplicated gene encoding autoantibody.
Restriction fragment length polymorphisms and single germline coding region sequence in VH18/2, a duplicated gene encoding autoantibody.
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VH18/2（编码自身抗体的重复基因）中的限制性片段长度多态性和单种系编码区序列。
DOI：
10.1016/0161-5890(93)90070-r
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发表时间：
1993
影响因子：
3.6
通讯作者：
Guillaume,T
中科院分区：
文献类型：
--
作者：
Rubinstein,DB;Symann,M;Stewart,AK;Guillaume,T
在这项研究中，我们分析了限制性片段长度多态性的VH 18 2，一个基因编码的抗DNA抗体的重链，并与该基因的编码区的种系序列。在严格条件下，将与CDR 1和与CDR 2基因片段的5 ′和3 ′两半互补的寡核苷酸探针与用XbaI消化的基因组DNA杂交，并用所有三种探针产生26、24和18 kb的多态性条带。个体在其基因组DNA中有一条、两条或三条共同的条带，表明VH 18 - 2基因在IgH基因座内的两个位点重复。虽然很难说这三个多态性基因片段中的哪一个构成等位基因对，但26和24 kb片段是最常见的（97%的个体具有一个或两个）。已知VH 18 2在表达的库中过度表达，与种系序列的核苷酸差异非常小。为了确定观察到的RFLP是否是由于VH 18 2编码区的序列多态性，以及表达基因的差异是否由体细胞突变引起，克隆并测序了含有该基因的大小选择的基因组DNA。在种系中发现了单一编码区序列。本研究的结果表明，VH 18 - 2的过度表达可能部分是由于其重复。与编码自身抗体的其他基因一样，VH 18 - 2在程序性免疫发育的早期表达，具有高度保守性、非多态性，可能有助于免疫库的建立或调节。
In this study, we analyze the restriction fragment length polymorphisms of VH 18 2, a gene encoding the heavy chain of an anti-DNA antibody, and correlate that with the germline sequence of the gene's coding region. Oligonucleotides probes complementary to the CDR1 and to both the 5'and 3'halves of the CDR2 gene segments were hybridized under stringent conditions to genomic DNA digested with Xbal, and yielded polymorphic bands of 26, 24 and 18 kb with all three probes. Individuals had either one, two, or three bands in common in their genomic DNA, indicating duplication of VH 18 2 genes at two sites within the IgH locus. While it is difficult to say which of the three polymorphic gene segments constitute an allelic pair, the 26 and 24 kb fragments were the most commonly seen (97% of individuals had one or both). VH 18 2 is known to be over-represented in the expressed repertoire with very little nucleotide divergence from the germline sequence. In order to determine whether the observed RFLPs are due to sequence polymorphism of the VH 18 2 coding region, and whether differences in the expressed genes arise from somatic mutation, size-selected genomic DNA containing the gene was cloned and sequenced. A single coding region sequence was found in the germline. The results of this study suggest that overexpression of VH 18 2 may in part be due to its duplication. Like other genes encoding autoantibody, which are well conserved, nonpolymorphic and expressed early in programmed immunologic development, VH 18 2 may be instrumental in the establishment or regulation of the immune repertoire.