Regulation of antigen-receptor gene assembly in hagfish
Regulation of antigen-receptor gene assembly in hagfish
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DOI：
10.1038/embor.2009.274
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发表时间：
2010-02-01
期刊：
影响因子：
7.7
通讯作者：
Nagawa, Fumikiyo
中科院分区：
文献类型：
--
作者：
Kishishita, Natsuko;Matsuno, Tatsuya;Nagawa, Fumikiyo
可变淋巴细胞受体（VLRs）是无颌脊椎动物七鳃鳗和盲鳗的抗原受体。VLR基因分为VLRA和VLRB，在七鳃鳗中，表达VLRA的淋巴细胞是T细胞样的，而表达VLRB的淋巴细胞是B细胞样的。不同的VLR基因在淋巴细胞中体细胞组装，然而，组装是如何调节的仍然是未知的。在这里，我们分析VLR基因组装在单细胞水平的近岸盲鳗（Eptatretus burgeri）。每个淋巴细胞只组装和转录一种类型的VLR基因，即VLRA或VLRB。在一般情况下，观察到的VLR单等位基因组装，但在某些情况下，发现双等位基因组装，其中许多，一个等位基因是功能和其他缺陷。事实上，所有VLR组装的淋巴细胞都含有至少一个功能性VLR基因。总之，这些结果表明VLR组装的反馈抑制和VLR阳性淋巴细胞的选择。
Variable lymphocyte receptors (VLRs) are antigen receptors in the jawless vertebrates lamprey and hagfish. VLR genes are classified into VLRA and VLRB, and lymphocytes expressing VLRA are T-cell-like, whereas those expressing VLRB are B-cell-like in the sea lamprey. Diverse VLR genes are assembled somatically in lymphocytes; however, how the assembly is regulated is still largely unknown. Here, we analyse VLR gene assembly at the single-cell level in the inshore hagfish (Eptatretus burgeri). Each lymphocyte assembles and transcribes only one type of VLR gene, either VLRA or VLRB. In general, monoallelic assembly of VLR was observed, but diallelic assembly was found in some cases-in many of which, one allele was functional and the other was defective. In fact, all VLR-assembled lymphocytes contained at least one functional VLR gene. Together, these results indicate a feedback inhibition of VLR assembly and selection of VLR-positive lymphocytes.