The fruitless (fru) gene in Drosophila plays a pivotal role in the formation of neural circuits underlying gender-specific behaviors. Specific labeling of fru expressing neurons has revealed a core circuit responsible for male courtship behavior.Females with a small number of masculinized neuronal clusters in their brain can initiate male-type courtship behavior. By examining the correlations between the masculinized neurons and behavioral gender type, a male-specific neuronal cluster,named P1, which coexpresses fru and double sex, was identified as a putative trigger center for male-type courtship behavior. P1 neurons extend dendrite to the lateral horn,where multimodal sensory inputs converge. Molecular studies suggest that fru determines the level of masculinization of neurons by orchestrating the transcription of a set of downstream genes, which remain to be identified.

中文翻译：

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果蝇的大脑性别差异和无果基因的功能。

果蝇中的无果（fru）基因在基于性别的特定行为的神经回路的形成中起着关键作用。Fru表达神经元的特殊标记揭示了负责男性求爱行为的核心电路。女性大脑中有少量男性化神经元簇的女性可以发起男性型求爱行为。通过检查男性化的神经元与行为性别类型之间的相关性，男性特有的神经元簇P1（共表达果蝇和双性行为）被确定为男性求爱行为的假定触发中心。P1神经元将树突延伸至侧角，多模式感官输入在此处汇聚。分子研究表明，fru通过协调一组下游基因的转录来确定神经元的男性化水平，