A novel P0 glycoprotein transgene activates expression of lacZ in myelin-forming Schwann cells
A novel P0 glycoprotein transgene activates expression of lacZ in myelin-forming Schwann cells
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DOI：
10.1046/j.1460-9568.1999.00568.x
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发表时间：
1999-05-01
影响因子：
3.4
通讯作者：
Wrabetz, L
中科院分区：
文献类型：
--
作者：
Feltri, ML;D'Antonio, M;Wrabetz, L
P-0糖蛋白是周围神经中最丰富的蛋白质，在雪旺细胞系中特异性表达。大鼠P-0基因上游1.1kb的DNA可以特异性地激活转基因小鼠雪旺细胞中cDNA的表达。然而，基于P-0启动子的转基因的表达一直不一致。与lacZ融合的多达9 kb的5'侧翼序列从未在多个品系的小鼠中产生可检测水平的β-半乳糖苷酶。我们描述了在外周神经中表达lacZ的转基因小鼠，使用完整的小鼠P-0基因，包括6 kb的5'侧翼序列，所有外显子和内含子，以及天然的多聚腺苷酸化信号。该载体在培养的雪旺细胞中特异性地激活lacZ表达，并且在六个转基因系中的四个中激活髓鞘形成雪旺细胞。在发育过程中和沃勒变性后，转基因表达均与内源性P-0基因的表达一致。lacZ表达低于内源性P-0表达，并且在存在低水平P-0 mRNA的神经嵴或许旺细胞前体中未检测到lacZ表达。然而，当相同的载体含有一个小的myc标签，而不是3.2 kb的lacZ插入，所得的转基因mRNA的表达水平与内源性P-0 mRNA相当。这些数据表明，基因内或3'侧翼序列是产生显着水平的内源性P-0基因表达所必需的。
P-0 glycoprotein, the most abundant protein in peripheral nerve, is expressed specifically in the Schwann cell lineage. Upstream of the rat P-0 gene 1.1 kb of DNA can activate expression of cDNAs specifically in Schwann cells in transgenic mice. However, the expression of P-0 promoter-based transgenes has been inconsistent. As much as 9 kb of 5' flanking sequence fused to lacZ never yielded detectable levels of beta-galactosidase in multiple lines of mice. We describe transgenic mice that express lacZ in peripheral nerve, using the complete mouse P-0 gene, including 6 kb of 5' flanking sequence, all exons and introns, and the natural polyadenylation signal. This vector activated lacZ expression specifically in cultured Schwann cells, and myelin-forming Schwann cells in four out of six transgenic lines. Transgene expression paralleled that of the endogenous P-0 gene, both during development and after Wallerian degeneration. lacZ expression was lower than endogenous P-0 expression, and was not detected in neural crest or Schwann cell precursors, where low levels of P-0 mRNA are present. However, when the same vector contained a small myc tag instead of the 3.2-kb lacZ insert, the resulting transgenic mRNA was expressed at levels comparable to endogenous P-0 mRNA. These data suggest that intragenic or 3' flanking sequences are necessary to generate the remarkable levels of endogenous P-0 gene expression.