Tohoku University Graduate School of Life Sciences, Sendai, 9808577, Japan.
Nat Commun. 2017 Nov 14;8(1):1480. doi: 10.1038/s41467-017-01623-z.
In fruit flies, the male-specific fruitless (fru) gene product FruBM plays a central role in establishing the neural circuitry for male courtship behavior by orchestrating the transcription of genes required for the male-type specification of individual neurons. We herein identify the core promoter recognition factor gene Trf2 as a dominant modifier of fru actions. Trf2 knockdown in the sexually dimorphic mAL neurons leads to the loss of a male-specific neurite and a reduction in male courtship vigor. TRF2 forms a repressor complex with FruBM, strongly enhancing the repressor activity of FruBM at the promoter region of the robo1 gene, whose function is required for inhibiting the male-specific neurite formation. In females that lack FruBM, TRF2 stimulates robo1 transcription. Our results suggest that TRF2 switches its own role from an activator to a repressor of transcription upon binding to FruBM, thereby enabling the ipsilateral neurite formation only in males.
在果蝇中，雄性特异性 fru 基因产物 FruBM 通过协调个体神经元雄性类型特化所需基因的转录，在建立雄性求偶行为的神经回路中发挥核心作用。我们在此确定核心启动子识别因子基因 Trf2 是 fru 作用的主要修饰因子。在性二态 mAL 神经元中敲低 Trf2 会导致雄性特异性神经突的丢失和雄性求偶活力的降低。TRF2 与 FruBM 形成一个抑制复合物，在 robo1 基因的启动子区域强烈增强 FruBM 的抑制活性，robo1 基因的功能是抑制雄性特异性神经突的形成。在缺乏 FruBM 的雌性果蝇中，TRF2 刺激 robo1 转录。我们的结果表明，TRF2 在与 FruBM 结合后，将其自身的转录作用从激活剂转换为抑制剂，从而仅在雄性中允许同侧神经突形成。
