University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu, Finland
University of Eastern Finland, Department of Environmental and Biological Sciences, P.O. Box 111, FI-80101 Joensuu, Finland.
J Exp Biol. 2018 Oct 24;221(Pt 20):jeb181412. doi: 10.1242/jeb.181412.
The sperm pre-fertilization environment has recently been suggested to mediate remarkable transgenerational consequences for offspring phenotype (transgenerational plasticity, TGB), but the adaptive significance of the process has remained unclear. Here, we studied the transgenerational effects of sperm pre-fertilization thermal environment in a cold-adapted salmonid, the European whitefish (). We used a full-factorial breeding design where the eggs of five females were fertilized with the milt of 10 males that had been pre-incubated at two different temperatures (3.5°C and 6.5°C) for 15 h prior to fertilization. Thermal manipulation did not affect sperm motility, cell size, fertilization success or embryo mortality. However, offspring that were fertilized with 6.5°C-exposed milt were smaller and had poorer swimming performance than their full-siblings that had been fertilized with the 3.5°C-exposed milt. Furthermore, the effect of milt treatment on embryo mortality varied among different females (treatment×female interaction) and male-female combinations (treatment×female×male interaction). Together, these results indicate that sperm pre-fertilization thermal environment shapes offspring phenotype and post-hatching performance and modifies both the magnitude of female (dam) effects and the compatibility of the gametes. Generally, our results suggest that short-term changes in sperm thermal conditions may have negative impact for offspring fitness. Thus, sperm thermal environment may have an important role in determining the adaptation potential of organisms to climate change. Detailed mechanism(s) behind our findings require further attention.
精子受精前的环境最近被认为可以介导后代表型的显著跨代效应（跨代可塑性，TGB），但其过程的适应意义仍不清楚。在这里，我们研究了冷适应鲑鱼欧洲白鲑（）精子受精前热环境的跨代效应。我们使用完全析因设计，其中 5 只雌鱼的卵子与 10 只雄鱼的精液受精，在受精前，这些雄鱼的精液在两个不同的温度（3.5°C 和 6.5°C）下孵育 15 小时。热处理不会影响精子活力、细胞大小、受精成功率或胚胎死亡率。然而，与受精时暴露于 3.5°C 的精液相比，受精时暴露于 6.5°C 的精液的后代体型较小，游泳能力较差。此外，精液处理对胚胎死亡率的影响因不同的雌鱼（处理×雌鱼互作）和雌雄鱼组合（处理×雌鱼×雄鱼互作）而异。总之，这些结果表明，精子受精前的热环境塑造了后代的表型和孵化后的表现，并改变了母本（雌鱼）效应的大小和配子的兼容性。一般来说，我们的结果表明，精子热条件的短期变化可能对后代的适应性产生负面影响。因此，精子热环境可能在决定生物体对气候变化的适应潜力方面发挥重要作用。我们研究结果背后的详细机制需要进一步关注。
