In Drosophila, changes to dietary protein elicit different body size responses between the sexes. Whether this sex difference in nutrient-dependent body size regulation extends to other nutrients, such as dietary sugar, remains unclear. Here, we show that reducing dietary sugar enhanced body size in Drosophila male and female larvae. Indeed, the largest body size was found in larvae reared in a diet without added sugar. Despite the equivalent body size effects of a low sugar diet between males and females, we detected sex-specific changes to the insulin/insulin-like growth factor (IIS) and target of rapamycin (TOR) signaling pathways. Further, we show that the metabolic changes observed in larvae reared on a low sugar diet differ between the sexes. Thus, despite identical phenotypic responses to dietary sugar in males and females, distinct changes to cell signaling pathways and whole-body metabolism were associated with the increased body size in each sex. This highlights the importance of including both sexes in all mechanistic studies on larval growth, as males and females may use different molecular and metabolic mechanisms to achieve similar phenotypic outcomes.

中文翻译：

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低糖饮食通过性别特异性机制增加男性和女性的果蝇体重。

在果蝇中，饮食蛋白质的变化会引起两性之间的不同体型反应。目前尚不清楚这种在营养物依赖性的体重调节中的性别差异是否会扩展到其他营养物，例如饮食糖。在这里，我们表明减少饮食中的糖会增加果蝇的体型雄性和雌性幼虫。确实，在不添加糖的饮食中饲养的幼虫中发现最大的体型。尽管低糖饮食在男性和女性之间具有同等的体重影响，但我们仍检测到了针对胰岛素/类胰岛素生长因子（IIS）和雷帕霉素（TOR）信号通路靶标的性别特异性变化。此外，我们表明，在低糖饮食饲养的幼虫中观察到的代谢变化在两性之间是不同的。因此，尽管男性和女性对饮食糖的表型反应相同，但细胞信号通路和全身代谢的明显变化与男女性别的增加有关。这凸显了在所有有关幼虫生长的机理研究中都包括性别的重要性，