Assessing risks of invasion through gamete performance: farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon

Adaptations at the gamete level (a) evolve quickly, (b) appear sensitive to inbreeding and outbreeding and (c) have important influences on potential to reproduce. We apply this understanding to problems posed by escaped farm salmon and measure their potential to reproduce in the wild. Farm Atlantic salmon (Salmo salar) are a threat to biodiversity, because they escape in large numbers and can introgress, dilute or disrupt locally adapted wild gene pools. Experiments at the whole fish level have found farm reproductive potential to be significant, but inferior compared to wild adults, especially for males. Here, we assess reproductive performance at the gamete level through detailed in vitro comparisons of the form, function, fertility, compatibility and competitiveness of farm versus wild Atlantic salmon sperm and eggs, in conditions mimicking the natural gametic microenvironment, using fish raised under similar environmental conditions. Despite selective domestication and reduced gene...配子水平上的适应性具有如下特征：(a) 演化速度较快；(b) 对近交与远交反应敏感；(c) 对个体繁殖潜能具有显著影响。我们将这一认知应用于逃逸养殖大西洋鲑所引发的问题，以评估它们在自然环境中的繁殖潜能。养殖大西洋鲑（Salmo salar）会对生物多样性造成威胁：其种群会大量逃逸，并可通过基因渐渗、基因稀释或破坏本地适应的野生基因库，对野生种群造成干扰。此前基于个体鱼水平的实验研究表明，养殖大西洋鲑的繁殖潜能可观，但相较于野生成体仍存在劣势，雄性个体的差距尤为明显。本研究通过模拟自然配子微环境，使用在相同养殖环境下培育的实验鱼，开展体外（in vitro）详细对比实验，对比分析养殖与野生大西洋鲑精子、卵子的形态、功能、受精能力、兼容性及竞争力，以此评估配子水平上的繁殖表现。尽管经过选择性驯化且基因多样性有所降低……