Fang Jie, Zhang Wen-Cheng, Yamashita Tetsuji, Gao Jiangang, Zhu Min-Sheng, Zuo Jian
Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
Genesis. 2012 Feb;50(2):124-31. doi: 10.1002/dvg.20810. Epub 2012 Jan 5.
Outer hair cells (OHCs) in the cochlea are crucial for the remarkable hearing sensitivity and frequency tuning. To understand OHC physiology and pathology, it is imperative to use mouse genetic tools to manipulate gene expression specifically in OHCs. Here, we generated two prestin knockin mouse lines: (1) the prestin-CreERT2 line, with an internal ribosome entry site-CreERT2-FRT-Neo-FRT cassette inserted into the prestin locus after the stop codon, and (2) the prestin-CreERT2-NN line, with the FRT-Neo-FRT removed subsequently. We characterized the inducible Cre activity of both lines by crossing them with the reporter lines CAG-eGFP and Ai6. Cre activity was induced with tamoxifen at various postnatal ages and only detected in OHCs, resembling the endogenous prestin expression pattern. Moreover, prestin-CreERT2+/-(heterozygotes) and +/+(homozygotes) as well as prestin-CreERT2-NN+/-mice displayed normal hearing. These two prestin-CreERT2 mouse lines are therefore useful tools to analyze gene function in OHCs in vivo.
耳蜗中的外毛细胞（OHCs）对于卓越的听力敏感性和频率调谐至关重要。为了理解外毛细胞的生理学和病理学，使用小鼠遗传工具在OHCs中特异性地操纵基因表达势在必行。在此，我们构建了两个prestin基因敲入小鼠品系：（1）prestin-CreERT2品系，在终止密码子后将一个内部核糖体进入位点-CreERT2-FRT-Neo-FRT盒插入prestin基因座；（2）prestin-CreERT2-NN品系，随后去除了FRT-Neo-FRT。我们通过将它们与报告基因品系CAG-eGFP和Ai6杂交来表征这两个品系的诱导型Cre活性。在不同的出生后年龄用他莫昔芬诱导Cre活性，且仅在OHCs中检测到，类似于内源性prestin表达模式。此外，prestin-CreERT2+/-（杂合子）和+/+（纯合子）以及prestin-CreERT2-NN+/-小鼠表现出正常听力。因此，这两个prestin-CreERT2小鼠品系是在体内分析OHCs中基因功能的有用工具。
