Data from: Food fight: sexual conflict over free amino acids in the nuptial gifts of male decorated crickets

In decorated crickets, Gryllodes sigillatus, the spermatophore that a male transfers at mating includes a gelatinous spermatophylax that the female consumes, delaying her removal of the sperm-filled ampulla. Male fertilization success increases with the length of time females spend feeding on the spermatophylax, while females may benefit by prematurely discarding the spermatophylaxes of undesirable males. This sexual conflict should favour males that produce increasingly appealing spermatophylaxes, and females that resist this manipulation. To determine the genetic basis of female spermatophylax feeding behaviour, we fed spermatophylaxes to females of nine inbred lines and found that female genotype had a major influence on spermatophylax feeding duration. The amino acid composition of the spermatophylax was also significantly heritable. There was a positive genetic correlation between spermatophylax feeding duration and the gustatory appeal of the spermatophylax. This correlation suggests that genes expressed in males that produce more manipulative spermatophylaxes are positively linked to genes expressed in females that make them more vulnerable to manipulation. Outbred females spent less time feeding on spermatophylaxes than inbred females, and thus showed greater resistance to male manipulation. Further, in a nonspermatophylax producing cricket (Acheta domesticus), females were significantly more prone to feeding on spermatophylaxes than outbred female Gryllodes. Collectively, these results suggest a history of sexually antagonistic coevolution over the consumption of nuptial food gifts.在装饰蟋蟀（Gryllodes sigillatus）中，雄性交配时传递的精包（spermatophore）包含一个胶状精营养体（spermatophylax），雌虫取食该结构会延迟其移除充满精子的精壶（ampulla）。雄性受精成功率随雌虫取食精营养体的时长增加而提升，而雌虫则可通过过早丢弃不受欢迎雄性的精营养体获益。这种性冲突（sexual conflict）理应青睐能够产生愈发诱人精营养体的雄性，以及能够抵抗此类操控的雌性。为探究雌虫取食精营养体行为的遗传基础，我们将精营养体饲喂给9个近交系（inbred lines）雌虫，结果发现雌虫基因型对其取食精营养体的时长具有显著主导影响。精营养体的氨基酸组成同样具有显著可遗传性。取食精营养体的时长与精营养体的味觉吸引力之间存在正向遗传相关。该相关表明，雄性体内负责产生更具操控性精营养体的基因，与雌虫体内使其更易受操控的基因呈正向连锁。远交系（outbred）雌虫取食精营养体的时长短于近交系雌虫，因此其对雄性操控的抵抗性更强。此外，在不产生精营养体的家蟋蟀（Acheta domesticus）中，雌虫取食精营养体的概率显著高于远交系装饰蟋蟀雌虫。综合上述结果，本研究表明围绕婚食礼物（nuptial food gifts）的取食行为，存在性拮抗协同进化（sexually antagonistic coevolution）的演化历史。