Balancer chromosomes, primarily discovered and used in Drosophila melanogaster, are valuable tools to maintain lethal mutations in a particular genomic segment. Full-length balancer chromosomes would be particularly useful because of the capacity to maintain whole genomic traits. However, murine full-length balancer chromosomes generated via a single Cre/loxP recombination are still not demonstrated. In this study, we developed a novel mouse strain with full-length inverted chromosome 17 (Ch17^Inv balancer) via a single Cre/loxP recombination event in mES cells. The Ch17^Inv balancer mice are viable and phenotypically normal. When bred with other strains, the haplotype of chromosome 17 can be stably maintained as determined by the high throughput SNPs assay. Interestingly, we found that the recombination events were efficiently reduced within the inverted region but not eliminated. The method established in this study can be applied to generate other full-length balancer chromosomes. Moreover, the Ch17^Inv balancer strain would be a valuable resource to maintain the entire chromosome 17 from different donor strains.

平衡染色体，主要在黑腹果蝇中发现和使用，是在特定基因组片段中维持致死突变的宝贵工具。由于能够保持整个基因组特征，全长平衡染色体将特别有用。然而，通过单个Cre/loxP重组产生的鼠全长平衡染色体仍未得到证实。在这项研究中，我们通过mES 细胞中的单个Cre/loxP重组事件开发了一种具有全长倒置染色体 17（Ch17 ^Inv平衡器）的新型小鼠品系。Ch17 ^Invbalancer 小鼠是有活力的并且表型正常。当与其他菌株繁殖时，17 号染色体的单倍型可以稳定保持，如高通量 SNP 测定所确定的。有趣的是，我们发现重组事件在倒置区域内有效减少，但并未消除。本研究中建立的方法可用于生成其他全长平衡器染色体。此外，Ch17 ^Inv平衡器菌株将是维持来自不同供体菌株的整个 17 号染色体的宝贵资源。