EXPRESSION OF A NOVEL TYPE OF IMMUNOGLOBULIN-C-LAMBDA TRANSCRIPTS IN HUMAN MATURE LYMPHOCYTE-B PRODUCING CHI-LIGHT CHAINS
EXPRESSION OF A NOVEL TYPE OF IMMUNOGLOBULIN-C-LAMBDA TRANSCRIPTS IN HUMAN MATURE LYMPHOCYTE-B PRODUCING CHI-LIGHT CHAINS
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DOI：
10.1002/eji.1830210237
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发表时间：
1991-02-01
影响因子：
5.4
通讯作者：
DAVI, F
中科院分区：
文献类型：
--
作者：
GUGLIELMI, P;DAVI, F
在 B 淋巴细胞个体发育过程中观察到免疫球蛋白基因（重链，然后是 aleph，最后是 lambda 基因）的有序重排。 出乎意料的是，我们发现产生aleph链并具有种系lambda基因的人类成熟B细胞含有由不变的5'区域（本文称为X）和经典C-lambda外显子之一组成的lambda mRNA。 这些转录物的 X 区域源自位于 J-C-lambda-1 基因片段上游 5 kb 的独特外显子。 X-C-lambda mRNA 表达无需体细胞 DNA 重排。 使用 X DNA 片段作为探针可以定义包含至少四个成员并包括 lambda-14.1 基因的第一个外显子的人类基因家族。 后者在前 B 淋巴细胞中选择性转录并指导 lambda 样链的合成。 相反，在成熟B细胞中，X-C-lambda转录物似乎不编码C-lambda相关多肽。 因此，尽管 73% 的同源性远远超出了外显子序列，但 X 和 lambda-14.1 基因在 B 细胞发育的不同阶段表达，并可能发挥不同的功能。
Ordered rearrangement of immunoglobulin genes (heavy chain then aleph and eventually lambda genes) is observed during B lymphocyte ontogeny. Unexpectedly, we found that human mature B cells producing aleph chains and having germ-line lambda genes contain lambda mRNA consisting of an invariant 5' region (herein termed X) and of one of the classical C-lambda exons. The X region of these transcripts originates from a unique exon located 5 kb upstream of the J-C-lambda-1 gene segment. X-C-lambda mRNA expression occurs without somatic DNA rearrangement. The use of the X DNA fragment as a probe allows definition of a family of human genes that comprises at least four members and includes the first exon of the lambda-14.1 gene. The latter is selectively transcribed in pre-B lymphocytes and directs the synthesis of a lambda-like chain. In contrast, the X-C-lambda transcripts do not appear to encode a C-lambda-related polypeptide in mature B cells. Thus, despite a 73% homology extending far beyond the exon sequences, the X and lambda-14.1 genes are expressed at different stages of B cell development and might serve different functions.