Gamete ecology in variable environments

可变环境中的配子生态

• 批准号: RGPIN-2016-04821
• 负责人: Purchase, Craig
• 金额: $ 2.04万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615323
• 关键词: Gamete; ecology; variable; environments

We have a poor understanding of when and how natural selection modifies the outcome of sexual selection (their interaction). This makes it difficult to predict the product of selection, a problem that is exacerbated under environmental perturbation. My long-term objective is to illuminate how natural selection via abiotic conditions and sexual selection through both males and females interact to influence gamete ecology and evolution. Males take risks to potentially mate and winners may be so successful that they become sperm deficient, yet due to post-copulatory sexual selection many fail to sire offspring. Sexual selection operates in both internal and external fertilizers, but external sperm also encounter natural selection, via variable abiotic conditions that modulate sperm behaviour. The interaction between sexual and natural selection at the gamete level is unexplored. Can males cheat female strategies? Can males influence sperm performance of rivals? Does any of this depend on abiotic conditions? Using external fertilizers, my research examines the interactions between male and female gametes experiencing both sexual and natural selection in the fertilization micro-environment. The research transcends species and provides insight into reproductive dynamics that have ecological (recruitment), evolutionary (hybridization) and conservation (captive breeding) implications. Progress will be achieved from 3 short-term objectives: (1) Males produce more sperm than are necessary for fertilization and for unknown reasons there is great within-ejaculate variation in sperm form and function. A fertilization tradeoff exists between sperm swimming speed and longevity, and these different sperm can influence offspring quality. However whether such patterns are influenced by abiotic conditions in external fertilizers is not known. My team will determine if sperm that maintain swimming longevity under stressful conditions produce superior quality offspring. (2) Recent discoveries of chemically modified sperm behaviour include female-cue mediated conspecific sperm preferences. We do not know how pliable the underpinnings of this are and thus the overall evolutionary importance. We will determine if mechanisms have costs and breakdown in populations where they are not needed, whether interactions with stressful abiotic conditions destroy sexual selection, and whether patterns are so evolutionarily important that they evolve at the intraspecific level. (3) The importance of seminal fluid chemistry to a male’s sperm function is known for some internal fertilizers, but how one’s seminal fluid influences other individuals is poorly understood. We will determine if seminal fluid alters processes of female mediated sperm competition, and if males that are chosen mates evolve mechanisms to reduce paternity of sneaker males that use alternative reproduction strategies.

我们对自然选择何时以及如何改变性选择的结果（它们的相互作用）的理解很差。这使得预测选择的结果变得困难，而这个问题在环境扰动下会变得更加严重。我的长期目标是阐明自然选择如何通过非生物条件和性选择通过男性和女性相互作用，以影响配子生态和进化。 雄性冒险寻找潜在的配偶，胜利者可能会如此成功，以至于他们变得缺乏精子，但由于交配后的性选择，许多人无法产生后代。性选择在内部和外部肥料中都起作用，但外部精子也会遇到自然选择，通过调节精子行为的可变非生物条件。性选择和自然选择在配子水平上的相互作用尚未被探索。男性可以欺骗女性的策略吗？男性可以影响竞争对手的精子性能吗？这一切都取决于非生物条件吗？ 使用外部肥料，我的研究探讨了在受精微环境中经历性选择和自然选择的雄性和雌性配子之间的相互作用。这项研究超越了物种，并提供了对生殖动力学的深入了解，这些生殖动力学具有生态（招募），进化（杂交）和保护（圈养繁殖）的影响。 将从3个短期目标取得进展： (1)雄性产生的精子多于受精所需的数量，并且由于未知的原因，精子的形式和功能在射精中存在很大的差异。精子游动速度和寿命之间存在受精权衡，这些不同的精子会影响后代质量。然而，这种模式是否受到外部肥料的非生物条件的影响尚不清楚。我的团队将确定在压力条件下保持游泳寿命的精子是否能产生上级质量的后代。 (2)最近发现的化学修饰的精子行为包括女性线索介导的同种精子偏好。我们不知道这一点的基础有多柔韧，因此也不知道整体进化的重要性。我们将确定机制是否有成本和在不需要它们的种群中的崩溃，与压力非生物条件的相互作用是否会破坏性选择，以及模式是否在进化上如此重要以至于它们在种内水平上进化。 (3)精液化学对男性精子功能的重要性是众所周知的一些内部肥料，但一个人的精液如何影响其他个体却知之甚少。我们将确定如果精液改变女性介导的精子竞争的过程中，如果男性选择的配偶进化机制，以减少父子关系的运动鞋男性使用替代生殖策略。