Transient expression of tyrosine hydroxylase promoter/reporter gene constructs in the olfactory epithelium of transgenic mice.
Transient expression of tyrosine hydroxylase promoter/reporter gene constructs in the olfactory epithelium of transgenic mice.
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转基因小鼠嗅觉上皮中酪氨酸羟化酶启动子/报告基因构建体的瞬时表达。
DOI：
10.1007/s11068-005-3336-9
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Baker,Harriet
中科院分区：
文献类型：
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作者：
Sasaki,Hayato;Berlin,Roseann;Baker,Harriet
假设嗅觉受体神经元（ORN）的成熟和存活取决于嗅上皮（OE）发育和再生过程中嗅球的营养支持。本研究在两个独立衍生的转基因小鼠品系中表征转基因表达，其中9 kb的酪氨酸羟化酶（TH）启动子用于驱动增强型绿色荧光蛋白（TH/eGFP）或LacZ（TH/β-gal）报告基因。转基因表达，发现主要是在背侧方面的OE，背侧隔和内鼻甲II，类似区一分布的嗅觉受体基因。标记细胞呈卵圆形至梭形，树突突出至上皮表面，但很少表现出可辨别的纤毛。轴突短，并没有超出基膜。由于只有一个细胞亚群含有嗅觉标记蛋白，指示ORN成熟，转基因表达细胞可能是不成熟的神经元前体。没有TH mRNA或蛋白质的转基因表达的证明与内源性TH的低基础水平转录活性一致，这可能反映TH和报告蛋白稳定性之间的差异。分子识别特定的嗅觉衍生的细胞群，PDE 2和LHRH，也没有共定位与任何报告。凋亡的新生转基因表达细胞的比例高于预期，这是成年小鼠明显缺乏的原因。这些研究支持这样的概念，即表现出假定的ORN的形态学和生物化学特征的转基因表达细胞不能成熟并经历凋亡细胞死亡，可能是因为它们缺乏营养支持。
Maturation and survival of olfactory receptor neurons (ORNs) are hypothesized to depend on trophic support from the olfactory bulb during both development and regeneration of the olfactory epithelium (OE). The current study characterized transgene expression in two independently derived transgenic mouse lines in which 9 kb of tyrosine hydroxylase (TH) promoter was utilized to drive either enhanced green fluorescent protein (TH/eGFP) or LacZ (TH/β-gal) reporters. Transgene expression, found primarily on dorsal aspects of the OE, the dorsal septum and endoturbinate II, resembled the Zone one distribution of olfactory receptor genes. Labeled cells were ovoid to fusiform with dendrites that projected to the epithelial surface but only rarely exhibited discernable cilia. Axons were short and did not extend beyond the basal lamina. As only a subpopulation of the cells contained olfactory marker protein, indicative of ORN maturation, the transgene expressing cells were likely immature neuronal precursors. Demonstration of transgene expression without either TH mRNA or protein was consistent with low basal level transcriptional activity of endogenous TH that may reflect differences between TH and reporter protein stability. Molecules identifying specific olfactory-derived cell populations, PDE2 and LHRH, also did not co-localize with either reporter. A higher than predicted proportion of apoptotic neonatal transgene-expressing cells accounted for their apparent paucity in adult mice. These studies support the concept that transgene expressing cells exhibiting morphological and biochemical characteristics of presumptive ORNs are unable to mature and undergo apoptotic cell death possibly because they lack trophic support.