TRANSCRIPTS OF THE IMMUNOGLOBULIN-C-MU GENE VARY IN STRUCTURE AND SPLICING DURING LYMPHOID DEVELOPMENT
TRANSCRIPTS OF THE IMMUNOGLOBULIN-C-MU GENE VARY IN STRUCTURE AND SPLICING DURING LYMPHOID DEVELOPMENT
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DOI：
10.1073/pnas.77.12.7400
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发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
ADAMS, JM
中科院分区：
文献类型：
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作者：
KEMP, DJ;HARRIS, AW;ADAMS, JM
小鼠IG恒定区（C. μ.）基因可以区分。而B细胞含有μ。2.4和2.7kb的mRNA，许多T淋巴瘤、Abelson前B淋巴瘤和骨髓肿瘤细胞系含有携带C μ的多腺苷酸化RNA种类。序列（C. μ. 1、2.3和3.0 kb的RNA）。生产C.M. RNA，不同于μ。mRNA不需要在连接区（JH）基因座内重组。为了定义C. μ. RNA，通过凝胶电泳分离来自代表性细胞系的RNA，转移到重氮苄氧基甲基纸上，并测试与23个DNA片段的杂交，所述DNA片段共同跨越染色体μ。基因，克隆自浆细胞瘤。所有的C.mu。RNA带有衍生自4个C μ.结构域，但没有一个包含分隔结构域的间插序列;因此每个都代表剪接的RNA种类。1.9kb的C. RNA含有分泌的μ RNA的特征性3“序列。链;较长的物种具有膜结合的μ链。链因此，C.mu. RNA和μmRNA在整个C μ中是等同的。和3“末端区域。它们在5 ″区明显不同，因为3.0和2.3kb的C. RNA携带来自常规JH-C μ.插入序列因为这些序列距离C μ有几kb，该区域必须含有至少1个迄今未被怀疑的剪接。C.mu. RNA可能不表达免疫多样性，因为没有证据表明它们具有可变区。T和前B淋巴样和髓样细胞含有等同的C μ。RNA种类，其与μ.某些前B和B淋巴系中的mRNA。C.mu. RNA表达似乎反映了C μ的激活状态。T细胞、B细胞和骨髓细胞发育早期细胞共有的基因。
Two classes of transcripts of the mouse Ig constant region (C.mu.) gene can be distinguished. Whereas B cells contain .mu. mRNA of 2.4 and 2.7 kilobases (kb), many T lymphoma, Abelson pre-B lymphoma and myeloid tumor cell lines contain polyadenylylated RNA species bearing C.mu. sequences (C.mu. RNA) of 1.9, 2.1, 2.3 and 3.0 kb. Production of C.mu. RNA, unlike .mu. mRNA, does not require recombination within the joining region (JH) locus. To define the structure of C.mu. RNA, RNA from representative cell lines was fractionated by gel electrophoresis, transferred to diazobenzyloxymethyl paper, and tested for hybridization with 23 DNA fragments that collectively span a chromosomal .mu. gene, cloned from a plasmacytoma. All the C.mu. RNA bear sequences derived from each of the 4 C.mu. domains, but none contain the intervening sequences separating domains; thus each represents a spliced RNA species. The 1.9 kb C.mu. RNA contains the 3'' sequence characteristic of secreted .mu. chain; the longer species bear that of membrane-bound .mu. chain. Hence C.mu. RNA and .mu. mRNA are equivalent throughout the C.mu. and 3'' terminal regions. They differ markedly in their 5'' regions, because the 3.0 and 2.3 kb C.mu. RNA bear sequences from within the conventional JH-C.mu. intervening sequence. Because these sequences are several kb from C.mu., this region must contain at least 1 hitherto unsuspected splice. C.mu. RNA may not express immunological diversity, because no evidence was found that they bear variable regions. T and pre-B lymphoid and myeloid cells contain equivalent C.mu. RNA species, which coexist with .mu. mRNA in some pre-B and B lymphoid lines. C.mu. RNA expression appears to reflect an activated state of the C.mu. gene common to cells at early stages of T, B and myeloid development.