Department of Environmental Toxicology and Department of Wildlife, Fish, and Conservation Biology, University of California, 4121 Meyer Hall, Davis, CA 95616, USA.
Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA, USA.
Proc Biol Sci. 2021 May 26;288(1951):20203118. doi: 10.1098/rspb.2020.3118. Epub 2021 May 19.
Salinity conditions in oyster breeding grounds in the Gulf of Mexico are expected to drastically change due to increased precipitation from climate change and anthropogenic changes to local hydrology. We determined the capacity of the eastern oyster, , to adapt via standing genetic variation or acclimate through transgenerational plasticity (TGP). We outplanted oysters to either a low- or medium-salinity site in Louisiana for 2 years. We then crossed adult parents using a North Carolina II breeding design, and measured body size and survival of larvae 5 dpf raised under low or ambient salinity. We found that TGP is unlikely to significantly contribute to low-salinity tolerance since we did not observe increased growth or survival in offspring reared in low salinity when their parents were also acclimated at a low-salinity site. However, we detected genetic variation for body size, with an estimated heritability of 0.68 ± 0.25 (95% CI). This suggests there is ample genetic variation for this trait to evolve, and that evolutionary adaptation is a possible mechanism through which oysters will persist with future declines in salinity. The results of this experiment provide valuable insights into successfully breeding low-salinity tolerance in this commercially important species.
由于气候变化导致降水增加和人为改变当地水文学，墨西哥湾牡蛎养殖场的盐度条件预计将发生巨大变化。我们确定了东方牡蛎，通过静态遗传变异来适应或通过跨代可塑性（TGP）来适应。我们将牡蛎种植到路易斯安那州的低盐度或中盐度地点 2 年。然后，我们使用北卡罗来纳州 II 代繁殖设计交叉成年父母，并测量在低或环境盐度下培养的 5 dpf 幼虫的体型和存活率。我们发现，TGP 不太可能显著提高对低盐度的耐受性，因为当亲代在低盐度环境中适应时，我们没有观察到在低盐度下饲养的后代的生长或存活率增加。然而，我们检测到了体型的遗传变异，估计遗传力为 0.68±0.25（95%置信区间）。这表明该性状有足够的遗传变异可以进化，并且进化适应是牡蛎在未来盐度下降时生存的一种可能机制。该实验的结果为成功培育这种商业上重要的物种的低盐度耐受性提供了有价值的见解。
