Data from: Sex-specific weight loss mediates sexual size dimorphism in Drosophila melanogaster

The selective pressures leading to the evolution of Sexual Size Dimorphism (SSD) have been well studied in many organisms, yet, the underlying developmental mechanisms are poorly understood. By generating a complete growth profile by sex in Drosophila melanogaster, we describe the sex-specific pattern of growth responsible for SSD. Growth rate and critical size for pupariation significantly contributed to adult SSD, whereas duration of growth did not. Surprisingly, SSD at peak larval mass was twice that of the uneclosed adult SSD with weight loss between peak larval mass and pupariation playing an important role in generating the final SSD. Our finding that weight loss is an important regulator of SSD adds additional complexity to our understanding of how body size is regulated in different sexes. Collectively, these data allow for the elucidation of the molecular-genetic mechanisms that generate SSD, an important component of understanding how SSD evolves.

导致性大小二态性（Sexual Size Dimorphism, SSD）演化的选择压力已在诸多生物中得到充分研究，但其背后的发育机制仍不甚明晰。本研究通过构建黑腹果蝇（Drosophila melanogaster）完整的性别特异性生长谱，阐明了介导SSD形成的性别特异性生长模式。生长速率与化蛹临界尺寸显著影响成虫阶段的SSD，而生长时长则无此作用。值得注意的是，幼虫质量峰值时的SSD是未羽化成虫SSD的两倍，幼虫质量峰值至化蛹阶段的体重减轻在最终SSD的形成过程中发挥了关键作用。我们发现体重减轻是SSD的重要调控因子，该发现为理解不同性别间的体型调控机制增添了新的复杂性。综上，本研究的数据有助于阐明调控SSD形成的分子遗传机制，而这正是理解SSD演化过程的重要组成部分。