Comparison of two related lines of tauGFP transgenic mice designed for lineage tracing.
Comparison of two related lines of tauGFP transgenic mice designed for lineage tracing.
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DOI：
10.1186/s12861-017-0149-x
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发表时间：
2017-06-29
影响因子：
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通讯作者：
West JD
中科院分区：
文献类型：
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作者：
Sharp L;Pratt T;MacKay GE;Keighren MA;Flockhart JH;Chandler EJ;Price DJ;Mason JO;West JD
TgTP6.3转基因在TP6.3小鼠中几乎无处不在地产生tauGFP报告融合蛋白，它在微管上的定位比可溶性GFP作为谱系标记具有一些优势。然而，TgTP6.3 Tg/Tg纯合子不能存活，TgTP6.3 Tg/ -半合子小于野生型。TP6.4小鼠携带TgTP6.4转基因，TgTP6.4是用与TgTP6.3相同的结构产生的，因此我们研究TgTP6.4是否比TgTP6.3有优势。尽管TgTP6.4 Tg/Tg纯合子在断奶前死亡，但TgTP6.4 Tg/ -半合子仍有活力和可育性，且只有雄性明显轻于野生型。TgTP6.4转基因在2细胞期产生tauGFP融合蛋白，在成人中广泛表达，但在包括部分神经组织在内的一些组织中，tauGFP荧光较弱或不存在。经过几年的育种，TgTP6.4转基因表达模式发生了变化，嵌合转基因表达在所有表达组织中越来越普遍。这种嵌合体被用于观察TgTP6.4 Tg/−半合子肾上腺皮质的克隆谱系，这些谱系在质量和数量上与之前报道的其他嵌合体转基因小鼠、x失活嵌合体和嵌合体的谱系相当。与TP6.4小鼠相比，TP6.3小鼠嵌合现象较少，仅在角膜上皮和肾上腺皮质中观察到嵌合现象。镶嵌表达使得TgTP6.4转基因不适合用作传统的细胞谱系标记，但这种镶嵌性为观察成体组织发育或维持过程中产生的克隆谱系提供了一个有用的系统。在相关转基因系之间嵌合现象的差异，如在TP6.3和TP6.4中所描述的，可能为研究转基因沉默机制提供一个有用的系统。本文的在线版本（doi:10.1186/ s128661 -017-0149-x）包含补充材料，可供授权用户使用。
The tauGFP reporter fusion protein is produced nearly ubiquitously by the TgTP6.3 transgene in TP6.3 mice and its localisation to microtubules offers some advantages over soluble GFP as a lineage marker. However, TgTP6.3 Tg/Tg homozygotes are not viable and TgTP6.3 Tg/− hemizygotes are smaller than wild-type. TP6.4 mice carry the TgTP6.4 transgene, which was produced with the same construct used to generate TgTP6.3, so we investigated whether TgTP6.4 had any advantages over TgTP6.3. Although TgTP6.4 Tg/Tg homozygotes died before weaning, TgTP6.4 Tg/− hemizygotes were viable and fertile and only males were significantly lighter than wild-type. The TgTP6.4 transgene produced the tauGFP fusion protein by the 2-cell stage and it was widely expressed in adults but tauGFP fluorescence was weak or absent in several tissues, including some neural tissues. The TgTP6.4 transgene expression pattern changed over several years of breeding and mosaic transgene expression became increasingly common in all expressing tissues. This mosaicism was used to visualise clonal lineages in the adrenal cortex of TgTP6.4 Tg/− hemizygotes and these were qualitatively and quantitatively comparable to lineages reported previously for other mosaic transgenic mice, X-inactivation mosaics and chimaeras. Mosaicism occurred less frequently in TP6.3 than TP6.4 mice and was only observed in the corneal epithelium and adrenal cortex. Mosaic expression makes the TgTP6.4 transgene unsuitable for use as a conventional cell lineage marker but such mosaicism provides a useful system for visualising clonal lineages that arise during development or maintenance of adult tissues. Differences in the occurrence of mosaicism between related transgenic lines, such as that described for lines TP6.3 and TP6.4, might provide a useful system for investigating the mechanism of transgene silencing. The online version of this article (doi:10.1186/s12861-017-0149-x) contains supplementary material, which is available to authorized users.