Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
Mouse Genome Engineering Core Facility, Vice Chancellor for Research Office, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Development. 2020 Jul 8;147(13):dev191015. doi: 10.1242/dev.191015.
Pan-otic CRE drivers enable gene regulation throughout the otic placode lineage, comprising the inner ear epithelium and neurons. However, intersection of extra-otic gene-of-interest expression with the CRE lineage can compromise viability and impede auditory analyses. Furthermore, extant pan-otic CREs recombine in auditory and vestibular brain nuclei, making it difficult to ascribe resulting phenotypes solely to the inner ear. We have previously identified as an otic placode-specific target of the FGFR2b ligands FGF3 and FGF10. We show here that is otic specific through E10.5, but is not required for hearing. We targeted to the stop codon, generating mice, and observed CRE activity throughout the otic epithelium and neurons, with little activity evident in the brain. Notably, recombination was detected in many FGFR2b ligand-dependent epithelia. We generated and conditional mutants, and activated an FGFR2b ligand trap from E17.5 to P3. In contrast to analogous mice generated with other pan-otic CREs, these were viable. Auditory thresholds were elevated in mutants, and correlated with cochlear epithelial cell losses. Thus, provides a useful complement to existing pan-otic CRE drivers, particularly for postnatal analyses.
全效性嗅嵴 CRE 驱动子可在整个耳嵴系（包括内耳上皮和神经元）中进行基因调控。然而，与 CRE 谱系交叉的额外靶基因表达会影响生存能力并阻碍听觉分析。此外，现有的全效性嗅嵴 CRE 在听觉和前庭脑核中发生重组，这使得难以将产生的表型完全归因于内耳。我们之前已经确定 是 FGFR2b 配体 FGF3 和 FGF10 的嗅嵴特异性靶基因。我们在这里表明， 从 E10.5 开始是嗅嵴特异性的，但对听力没有要求。我们将 靶向到 终止密码子，生成 小鼠，并观察到 CRE 在整个耳嵴上皮和神经元中具有活性，但在大脑中活性很少。值得注意的是，在许多 FGFR2b 配体依赖性上皮中检测到了重组。我们生成了 和 条件性突变体，并从 E17.5 到 P3 激活 FGFR2b 配体陷阱。与使用其他全效性嗅嵴 CRE 生成的类似小鼠相比，这些突变体是存活的。听觉阈值在突变体中升高，并与耳蜗上皮细胞损失相关。因此， 为现有的全效性嗅嵴 CRE 驱动子提供了有用的补充，特别是用于产后分析。
