Key Points The UBC-GFP transgene is inserted next to the MHC locus on mouse chromosome 17. UBC-GFP BALB/cBy congenic mice retain their founder UBC-GFP C57BL/6 MHC haplotype. GFP is frequently used as a marker for tracking donor cells adoptively transplanted into recipient animals. The human ubiquitin C promoter (UBC)–driven-GFP transgenic mouse is a commonly used source of donor cells for this purpose. This mouse was initially generated in the C57BL/6 inbred strain and has been backcrossed into the BALB/cBy strain for over 11 generations. Both the C57BL/6 inbred and BALB/cBy congenic UBC-GFP lines are commercially available and have been widely distributed. These UBC-GFP lines can be a convenient resource for tracking donor cells in both syngenic MHC-matched and in allogenic MHC-mismatched studies as C57BL/6 (H-2b) and BALB/cBy (H-2d) have disparate MHC haplotypes. In this report, we surprisingly discover that the UBC-GFP BALB/cBy congenic mice still retain the H-2b MHC haplotype of their original C57BL/6 founder, suggesting that the UBC-GFP transgene integration site is closely linked to the MHC locus on chromosome 17. Using linear amplification–mediated PCR, we successfully map the UBC-GFP transgene to the MHC locus. This study highlights the importance and urgency of mapping the transgene integration site of transgenic mouse strains used in biomedical research. Furthermore, this study raises the possibility of alternative interpretations of previous studies using congenic UBC-GFP mice and focuses attention on the necessity for rigor and reproducibility in scientific research.

中文翻译：

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将 UBC-GFP 小鼠的 GFP 转基因的染色体插入位点映射到 MHC 基因座

关键点 UBC-GFP 转基因被插入到小鼠 17 号染色体上的 MHC 基因座旁边。UBC-GFP BALB/cBy 同类小鼠保留了它们的创始人 UBC-GFP C57BL/6 MHC 单倍型。GFP 经常被用作跟踪过继移植到受体动物的供体细胞的标记。人泛素 C 启动子 (UBC) 驱动的 GFP 转基因小鼠是用于此目的的常用供体细胞来源。该小鼠最初是在 C57BL/6 近交品系中产生的，并且已经回交到 BALB/cBy 品系中超过 11 代。C57BL/6 近交系和 BALB/cBy 同类 UBC-GFP 品系均可在市场上买到并已广泛分布。由于 C57BL/6 (H-2b) 和 BALB/cBy (H-2d) 具有不同的 MHC 单倍型，这些 UBC-GFP 系可以成为在同基因 MHC 匹配和同种异体 MHC 错配研究中跟踪供体细胞的方便资源。在本报告中，我们惊讶地发现 UBC-GFP BALB/cBy 同类小鼠仍然保留其原始 C57BL/6 创始人的 H-2b MHC 单倍型，这表明 UBC-GFP 转基因整合位点与 MHC 基因座密切相关17 号染色体。使用线性扩增介导的 PCR，我们成功地将 UBC-GFP 转基因定位到 MHC 基因座。这项研究强调了绘制生物医学研究中使用的转基因小鼠品系的转基因整合位点的重要性和紧迫性。此外，