Data from: Quantifying variation in female internal genitalia: no evidence for plasticity response to sexual conflict risk in a seed beetle

Sexually antagonistic coevolution can drive the evolution of male traits that harm females, and female resistance to those traits. While males have been found to vary their harmfulness to females in response to social cues, whether female resistance traits vary in response to social cues remains to be examined. Among seed beetles, male genital spines harm females during copulation and females might resist male harm via thickening of the reproductive tract walls. Here we develop a novel Micro-CT imaging technique to quantify female reproductive tract thickness in 3-dimensional space. We compared the reproductive tracts of female Callosobruchus maculatus from populations that had evolved under high and low levels of sexual conflict, and for females reared under a social environment that predicted either high or low levels of sexual conflict. We show that neither social environment nor evolutionary history significantly affected reproductive tract thickness. Our novel methodology allows for the measurement of fine-scale changes in the internal female reproductive tract, and will allow future investigations into the internal organs of insects and other animals.

性拮抗协同进化能够推动两类演化进程：一是产生伤害雌性的雄性性状，二是雌性演化出针对这些性状的抗性机制。尽管已有研究发现雄性可根据社会线索调整其对雌性的伤害程度，但雌性抗性性状是否会响应社会线索发生变化，仍有待验证。在豆象类昆虫中，雄性生殖器棘刺会在交配过程中对雌性造成伤害，而雌性或可通过增厚生殖道壁来抵御雄性的伤害。本研究开发了一种新型显微计算机断层扫描（Micro-CT）成像技术，以量化雌性生殖道厚度的三维空间分布特征。我们比较了雌性绿豆象（Callosobruchus maculatus）的生殖道，这些个体分别来自两类群体：一类是在高低不同性冲突水平下演化的种群，另一类是在预示高或低性冲突水平的社会环境中饲养的个体。研究结果表明，社会环境与演化历史均未对生殖道厚度产生显著影响。本研究开发的新型方法可实现雌性生殖道内部的精细尺度变化测量，未来也可应用于昆虫及其他动物的内部器官研究。