ORGANIZATION OF HUMAN-IMMUNOGLOBULIN HEAVY-CHAIN DIVERSITY GENE LOCI
ORGANIZATION OF HUMAN-IMMUNOGLOBULIN HEAVY-CHAIN DIVERSITY GENE LOCI
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DOI：
10.1002/j.1460-2075.1988.tb03309.x
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发表时间：
1988-12-20
期刊：
影响因子：
11.4
通讯作者：
KUROSAWA, Y
中科院分区：
文献类型：
--
作者：
ICHIHARA, Y;MATSUOKA, H;KUROSAWA, Y
免疫球蛋白重链的可变区由种系基因组上的三个独立基因编码：可变（VH）、多样性（DH）和连接（JH）基因。大多数人DH基因编码9-kb重复序列。我们确定了一个15 kb的DNA片段的核苷酸序列，其中包含超过一个半的这些重复单元，并确定了12个不同的DH基因。根据DH编码区及其周围区域的序列相似性，将它们分为6个不同的DH基因家族（DXP、DA、DK、DN、DM和DLR）。不同科的DH基因核苷酸序列差异较大，而同一科的DH基因核苷酸序列保守性较好。由于含有含有6个DH基因的6个DH的9-kb DNA至少被乘以5倍，因此DH基因的总数必须为约。30.这些DH基因被12个核苷酸的间隔信号夹在中间。在公开的VH-DH-JH结构中发现的大多数体细胞DH序列（体细胞DH区段被定义为不由种系VH或JH基因编码的区域）被分配给种系DH基因之一。然而，除了这些典型的DH基因，我们发现了一种新的DH基因（我们称之为DH基因），其相邻信号的间隔区长度是不规则的。该基因似乎通过倒位或缺失参与DIR-DH或DH-DH的连接。体细胞DH序列中的两个被分配到p53基因。因此，长的N片段可能起源于染色体组基因。
The variable region of immunoglobulin heavy chain is encoded by three separate genes on the germline genome: variable (VH), diversity (DH) and joining (JH) genes. Most human DH genes are encoded in 9-kb repeating sequences. We determined the nucleotide sequence of a 15-kb DNA fragment containing more than one and a half of these repeating units, and identified 12 different DH genes. Based on the sequence similarities of DH coding and the surrounding regions, they can be classified into six different DH gene families (DXP, DA, DK, DN, DM and DLR). Nucleotide sequences of DH genes belonging to different families diverge greatly, while those belonging to the same families are well conserved. Since the 9-kb DNA containing the six DH containing the six DH genes are multiplied at least five times, the total number of DH genes must be .apprx. 30. These DH genes are sandwiched by 12-nucleotide spacer signals. Most of the somatic DH sequences found in the published VH-DH-JH structures (the somatic DH segment being defined as the region which is not encoded either by germline VH or JH gene) were assigned to one of the germline DH genes. Other than these typical DH genes, however, we found a new kind of DH gene (which we termed DIR) the spacer lengths of whose neighbouring signals were irregular. The DIR gene appears to be involved in DIR-DH or DH-DIR joining by inversion or deletion. Two of the somatic DH sequences were assigned to the DIR genes. Long N segments might, therefore, originate from DIR genes.