Environmental genomics of adaptive phenotypic plasticity for temperature in threespine stickleback (Gasterosteus aculeatus)

生物将如何应对未来的气候变化？情景包括物种范围的改变、迁徙、灭绝和适应。适应的一种形式是“适应性表型可塑性”，当生物体有能力改变其表型（其内部或外部特征）以适应不断变化的环境，从而在每种环境中保持生产能力时，就会发生适应性表型可塑性。最近的研究表明，非塑料种群在应对气候变化方面将比塑料种群更加困难。尽管适应性表型可塑性因此可能是维持未来生物多样性的重要因素，但人们对其在基因组水平上的作用知之甚少。三刺棘鱼是研究可塑性选择基因的理想模式生物。阿拉斯加和不列颠哥伦比亚省的海洋棘鱼种群在最后一次冰期高峰（大约1.2万年前）之后入侵淡水，经历了比海洋环境更高的高温和更低的低温。通过在不同的温度下饲养海洋和淡水棘鱼，并使用强大的基因组学工具（微阵列和反向遗传学），我们不仅可以确定选择是否增加了淡水种群的可塑性，还可以确定负责的基因的数量和位置。此外，40年前，入侵的棘鱼种群在阿尔伯塔省定居。通过比较入侵种群及其来源的可塑性，我们可以进一步缩小那些负责适应性表型可塑性的基因的范围。本研究将确定表型可塑性对鱼类性能的整体基因组效应，并将阐明可塑性在使鱼类在不断变化的环境中持续生存方面所起的作用。通过研究刺鱼适应性表型可塑性的遗传学，我们对加拿大的生物多样性将如何受到未来气候变化的影响有了重要的认识。

How will organisms respond to future climate change? Scenarios include altered species' ranges, migration, extinction and adaptation. One form of adaptation, 'adaptive phenotypic plasticity', occurs when an organism has the ability to alter its phenotype (its internal or external characteristics) to match a changing environment such that it remains productive in each environment. Recent studies suggest that non-plastic populations will have a more difficult time coping with climate change than plastic populations. Although adaptive phenotypic plasticity could therefore be an important factor in maintaining future biodiversity, little is known about how it works on a genomic level. The threespine stickleback is an ideal model organism for studying the genes that are selected for plasticity. Marine populations of stickleback in Alaska and BC invaded freshwater after the last glacial maximum (approximately 12 000 years ago) and experienced higher high and lower low temperatures than in the marine environment. By raising marine and freshwater stickleback at different temperatures and using powerful genomics tools (microarrays and reverse genetics), we can not only determine whether selection has increased the plastic ability of freshwater populations, but we can identify the number and location of the genes responsible. Furthermore, an invasive stickleback population colonized Alberta 40 years ago. By comparing plasticity between the invasive population and its source of origin, we can further narrow in on those genes responsible for adaptive phenotypic plasticity. This research will determine the overall genomic effects of phenotypic plasticity on fish performance, and will elucidate the role that plasticity has played in enabling fish to persist in a changing environment. By studying the genetics of adaptive phenotypic plasticity in stickleback, we gain critical insight into how Canada's biodiversity will be affected in light of future climate change.