SYNCHRONOUS EXPRESSION OF LINE-1 RNA AND PROTEIN IN MOUSE EMBRYONAL CARCINOMA-CELLS
SYNCHRONOUS EXPRESSION OF LINE-1 RNA AND PROTEIN IN MOUSE EMBRYONAL CARCINOMA-CELLS
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DOI：
10.1128/mcb.13.9.5383
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发表时间：
1993-09-01
影响因子：
5.3
通讯作者：
BRANCIFORTE, D
中科院分区：
文献类型：
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作者：
MARTIN, SL;BRANCIFORTE, D
L1，或称LINE-1，是在所有哺乳动物基因组中发现的重复DNA家族。L1家族中至少有几个单独的成员是功能性转座元件。这些活性元件的表达导致新的L1通过反转录转位插入到基因组DNA中。我们在小鼠胚胎癌细胞系中检测到全长、义链Ll RNA转录本和l1编码蛋白的共表达。这两种L1表达产物都是逆转录过程中的中间产物。L1蛋白存在于细胞质聚集体中，不局限于任何已知的细胞器。选择六种胚胎癌细胞系进行测试，以代表早期小鼠胚胎发生中不同发育途径的承诺。在这六种细胞系中，仅有的两种表达L1的细胞系是独特的，因为它们具有向胚外内胚层分化的强烈倾向。这一观察结果与L1在小鼠原始生殖细胞中的表达和转位一致。这些研究的一个重要意义是，L1表达可能为确定小鼠胚胎发生过程中原始生殖细胞的起源提供了一个新的标记。
L1, or LINE-1, is a repetitive DNA family found in all mammalian genomes that have been examined. At least a few individual members of the L1 family are functional transposable elements. Expression of these active elements leads to new insertions of L1 into the genomic DNA by the process of retrotransposition. We have detected coexpression of full-length, sense-strand Ll RNA transcripts and L1-encoded protein in mouse embryonal carcinoma cell lines. Both of these L1 expression products are candidates for intermediates in the retrotransposition process. L1 protein is found in what appear to be cytoplasmic aggregates and is not localized to any known cytoplasmic organelles. The six embryonal carcinoma cell lines tested were chosen to represent commitment to different developmental pathways in early mouse embryogenesis. The only two cell lines that express L1 are unique among the six in that they have a strong predilection to differentiate into extraembryonic endoderm. This observation is consistent with L1 expression and transposition in primordial germ cells of the mouse. An important implication of these studies is that L1 expression may provide a new marker for use in determining the origin of primordial germ cells during mouse embryogenesis.