Laboratory for Integrated Neuroscience, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, United States.
Front Neural Circuits. 2018 Sep 11;12:68. doi: 10.3389/fncir.2018.00068. eCollection 2018.
Cre-P conditional knockout animals have become a prominent tool to understand gene function in discrete cell-types and neural circuits. However, this technology has significant limitations including off target cre-dependent recombination. The Rgs9cre strain has been used to generate a conditional knockout in striatal medium spiny neurons, but, as presented in the current study, off target recombination in the germline results in nonconditional deletion of P alleles. Using a Rem2 conditional allele, germline deletion (GD) was observed in a sex dependent manner. When Cre and P alleles were co-inherited from the female parent, 27 of 29 P alleles were recombined, but when co-inherited from the male parent, 5 of 36 P alleles were recombined. Rem2 expression measured by RT-qPCR confirmed nonconditional recombination in extrastriatal nuclei. Cre- is a powerful technique to modify genomic DNA (gDNA), however careful characterization of these mice is required to confirm control of conditional recombination.
Cre-P 条件性基因敲除动物已成为研究特定细胞类型和神经回路中基因功能的重要工具。然而，该技术存在显著的局限性，包括脱靶 Cre 依赖性重组。Rgs9cre 品系已被用于生成纹状体中型棘突神经元的条件性基因敲除，但正如当前研究所示，种系中的脱靶重组导致 P 等位基因的非条件缺失。使用 Rem2 条件性等位基因，观察到以性别依赖的方式发生种系缺失（GD）。当 Cre 和 P 等位基因均从母本遗传时，29 个 P 等位基因中有 27 个发生重组，但当从父本遗传时，36 个 P 等位基因中有 5 个发生重组。通过 RT-qPCR 测量的 Rem2 表达证实了纹状体外核中非条件性重组。Cre-是一种强大的基因座特异性基因组 DNA（gDNA）修饰技术，但需要对这些小鼠进行仔细的特征分析，以确认条件性重组的控制。
