Olfactory sensory neurons (OSNs) are bipolar neurons, unusual because they turn over continuously and have a multiciliated dendrite. The extensive changes in gene expression accompanying OSN differentiation in mice are largely known, especially the transcriptional regulators responsible for altering gene expression, revealing much about how differentiation proceeds. Basal progenitor cells of the olfactory epithelium transition into nascent OSNs marked by Cxcr4 expression and the initial extension of basal and apical neurites. Nascent OSNs become immature OSNs within 24-48 h. Immature OSN differentiation requires about a week and at least 2 stages. Early-stage immature OSNs initiate expression of genes encoding key transcriptional regulators and structural proteins necessary for further neuritogenesis. Late-stage immature OSNs begin expressing genes encoding proteins important for energy production and neuronal homeostasis that carry over into mature OSNs. The transition to maturity depends on massive expression of one allele of one odorant receptor gene, and this results in expression of the last 8% of genes expressed by mature OSNs. Many of these genes encode proteins necessary for mature function of axons and synapses or for completing the elaboration of non-motile cilia, which began extending from the newly formed dendritic knobs of immature OSNs. The cilia from adjoining OSNs form a meshwork in the olfactory mucus and are the site of olfactory transduction. Immature OSNs also have a primary cilium, but its role is unknown, unlike the critical role in proliferation and differentiation played by the primary cilium of the olfactory epithelium's horizontal basal cell.

中文翻译：

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嗅觉感觉神经元及其纤毛的成熟。

嗅觉感觉神经元（OSN）是双极神经元，由于它们连续翻转并具有多纤毛的树突而异常，因此很不寻常。伴随OSN分化的小鼠，基因表达的广泛变化已广为人知，尤其是负责改变基因表达的转录调节因子，揭示了分化如何进行的许多信息。嗅上皮的基础祖细胞转变为新生的OSN，其特征为Cxcr4表达以及基底和顶端神经突的初始延伸。新生的OSN在24-48小时内变为不成熟的OSN。不成熟的OSN分化需要大约一周的时间，至少需要两个阶段。早期未成熟的OSN会启动编码关键转录调节因子的基因的表达，以及进一步神经突形成所必需的结构蛋白。晚期未成熟OSN开始表达编码蛋白质的基因，这些蛋白质对于能量产生和神经元稳态起重要作用，这些蛋白质会延续到成熟的OSN中。向成熟的过渡取决于一个气味受体基因的一个等位基因的大量表达，这导致了成熟OSN表达的最后8％基因的表达。这些基因中的许多编码的蛋白是轴突和突触的成熟功能或完成非活动性纤毛形成所必需的蛋白质，纤毛从不成熟的OSN的新形成的树突状结开始延伸。来自相邻OSN的纤毛在嗅觉粘液中形成网状结构，并且是嗅觉转导的部位。未成熟的OSN也具有初级纤毛，但其作用尚不清楚，