Sexual conflicts often arise between mating partners because each sex tries to maximize its own reproductive success. One major male strategy to influence a partner's resource allocation is the transfer of accessory gland proteins. This has been shown to occur in simultaneous hermaphrodites as well as in organisms with separate sexes. Although accessory gland proteins affect the investment of resources in both male and female function, we here specifically focus on female investment. In the great pond snail, Lymnaea stagnalis, previous studies found that the accessory gland protein ovipostatin reduced female fecundity by suppressing egg laying in the partner in the short term (days). To investigate whether this reduction in egg laying is a commonly found effect of mating in freshwater snails, we compared egg output for evidence of suppression in isolated and paired snails of eight pulmonate species. Furthermore, we determined whether the suppression of egg laying caused a shift in resource allocation to the eggs. We found that in five of the eight species egg laying was suppressed, with fewer and lighter egg masses being laid when they had access to a mating partner. In mated pairs of L. stagnalis and Biomphalaria alexandrina, allocation of resources to the eggs was altered in opposite ways: individuals of L. stagnalis laid fewer but larger and heavier eggs; individuals of B. alexandrina laid smaller and lighter eggs, with no change in egg numbers. Such changes in the female function are most likely the result of combined effects of receiving accessory gland proteins, and the cost of mating in both male and female roles. Thus, effects of the maternal environment, including the receipt of accessory gland proteins, on offspring investment are not restricted to species with separate sexes.

中文翻译：

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交配对雌雄同体淡水蜗牛雌性繁殖的影响

交配对象之间经常发生性冲突，因为每个性别都试图最大限度地提高自己的繁殖成功率。影响伴侣资源分配的一项主要男性策略是辅助腺蛋白的转移。这已被证明发生在同时发生的雌雄同体以及具有不同性别的生物体中。尽管辅助腺蛋白会影响男性和女性功能的资源投资，但我们在这里特别关注女性投资。在大型池塘蜗牛 Lymnaea stagnalis 中，先前的研究发现，辅助腺蛋白 ovipostatin 通过在短期（数天）内抑制伴侣产卵来降低雌性繁殖力。为了研究这种产卵减少是否是淡水蜗牛交配的常见影响，我们比较了 8 种 pulmonate 物种的分离和配对蜗牛的卵子产量抑制证据。此外，我们确定了抑制产卵是否导致资源分配给鸡蛋的转变。我们发现，在八种物种中的五种中，产卵受到抑制，当它们与交配对象接触时，产卵量更少、重量更轻。在交配的 L. stagnalis 和 Biomphalaria alexandrina 中，资源对卵的分配发生了相反的变化：L. stagnalis 个体产下的卵更少但更大更重；B. alexandrina 个体产下的卵更小更轻，卵数没有变化。雌性功能的这种变化很可能是接受辅助腺蛋白的综合作用的结果，以及男性和女性角色交配的成本。因此，