Subtype specification of the olfactory sensory neurons in Drosophila by RUNX family transcription factor Lozenge

果蝇的嗅觉神经元分为50个不同的类别，每个类别都表达特定的气味受体，并共同参与检测和区分环境中的无数气味化学物质。为了揭示产生这种神经元多样性的发育机制，我分析了两种分子的功能; Runx家族转录因子Lozenge和Evi 1原癌基因哈姆雷特的果蝇同源物。发现嗅感觉神经元的前体细胞在发育过程中不断分化，而Lozenge水平逐渐降低。这使得在不同时间点分化的前体细胞接受不同水平的锭剂，从而产生不同类别的嗅觉感觉神经元。我还发现，哈姆雷特通过表观遗传机制改变Notch靶基因的表达，从而促进单个前体细胞产生不同类别的嗅觉感觉神经元的过程。

Olfactory sensory neurons in Drosophila melanogaster are diversified into 50 different classes, each expressing specific odorant receptors, and together contributing to detection and discrimination of a myriad of odorous chemicals in environment. To reveal the developmental mechanisms that generate this neuronal diversity, I analyzed the function of two molecules ; Runx-family transcription factor Lozenge and Drosophila homologue of Evi1 proto-oncogene Hamlet. I found that the precursor cells for the olfactory sensory neurons differentiate continuously while Lozenge level gradually decreases during development. This makes precursor cells that are differentiated at different time points receive different levels of Lozenge, thereby generating different classes of olfactory sensory neurons. I also found that Hamlet contributes to the process of a single precursor cell generating different classes of olfactory sensory neurons, by modifying the expression of the Notch-target genes through epigenetic mechanisms.