DISSERTATION RESEARCH: Sperm use and strategic sperm allocation in a Hawaiian swordtail cricket

在许多物种中，雌性与不止一个雄性交配。这导致了精子竞争，几个雄性的精子竞争使雌性的卵子受精。在其他条件相同的情况下，提供更多精子的男性预计会获得更多的受精。然而，雌性交配的次数以及雌性平等地利用雄性精子使卵子受精的程度也会影响到雄性的受精率。由于精子的产生需要生理成本，因此男性应该将不同数量的精子分配给不同的女性。为了预测任何物种的这些模式，研究人员需要关于雌性交配频率和它们如何使用精子的信息。这项研究将为一种夏威夷蟋蟀提供这些信息，并将用它来预测该物种雄性精子的分配模式。为了确定雌性的交配率，将在半自然的野外条件下每天观察单独标记的雌性，持续10周。为了确定精子的使用模式，研究人员将每天收集卵子，并使用遗传工具来识别精子。这些数据将在野生雌性中得到证实，再次使用遗传工具，估计配偶和后代的数量，为它们的精子储存和后代做出贡献。这项工作将提供在野外操作的性选择参数的信息，这是很少收集到的关键数据。研究人员将在夏威夷、纽约州北部的一所女子监狱参加一天的科学教育活动，并在康奈尔大学（Cornell）从一个代表性不足的群体中聘请一名本科生研究助理。

In many species, females mate with more than one male. This leads to sperm competition, where the sperm of several males compete to fertilize a female's eggs. All else equal, males that provide more sperm are expected to gain more fertilizations. However, the number of times a female mates and the extent to which she uses each male's sperm equally to fertilize her eggs also affect the number of fertilizations a given male is likely to achieve. Because sperm production entails a physiological cost, males are therefore expected to allocate different numbers of sperm to different females. In order to make predictions about these patterns in any species, investigators need information about how frequently females mate and how they use sperm. This research will provide that information for a species of Hawaiian cricket and will use it to predict patterns of male sperm allocation in this species. To determine female mating rate, individually marked females will be observed daily under semi-natural field conditions for ten weeks. To determine patterns of sperm use, the investigators will collect eggs daily and use genetic tools to identify the sires. These data will be corroborated in wild females by estimating, again using genetic tools, the number of mates and sires contributing to their sperm stores and offspring. This work will provide information on the sexual selection parameters operating in the field, crucial data that are rarely collected. The researchers will conduct outreach in Hawaii, in upstate New York by participating in a day of science education at a correctional facility for girls, and at Cornell by hiring an undergraduate research assistant from an underrepresented group.