Acclimatization and adaptation are key in animal physiology, particularly for ectotherms like fish. For example, cod adjust to both cold winters and warm summers. In laboratory settings, we acclimate animals to new conditions well before experiments begin. Adaptation, on the other hand, is typically viewed as an evolutionary process spanning generations. Unlike natural climate fluctuations, human-induced climate change is rapid, potentially increasing the need for swift adaptation. Lessons from paleobiology suggest that species risk extinction if they adapt too slowly.
For organizations such as ICES, there is a need to predict how fish populations will adapt to changing climates, including potential impacts on harvest levels. Simple projections of fish recruitment may be inadequate without considering the principles of adaptation, indicating that production models might need to account for new "regimes." This underscores the need for more fundamental knowledge to enhance model accuracy in the context of climate change. Molecular biology offers promising methods to explore adaptation mechanisms, though it is currently underused for marine commercial species.
In this Editor's choice article, researchers examined how sea temperature changes during the gametogenesis of Atlantic cod affect genetic instructions , particularly maternally deposited mRNAs that govern early embryonic development. The results were compelling; increased sea temperatures led to significant changes in maternal mRNA levels in embryos, indicating that these adjustments occur within the ovarian follicle cells months before spawning.
This research into early genetic indicators and their influence on embryonic development is crucial for predicting how species like cod will adapt to climate change. Some genes identified as temperature-sensitive in this study are known in the mammalian literature as maternal-effect-genes, which affect traits later in life. The regulation of maternal mRNAs, as shown in this study, points to a rapid adaptation mechanism that prepares the next generation for the mother's environmental conditions, highlighting a complex and immediate adaptation process.
Read the full paper, Ocean warming shapes embryonic developmental prospects of the next generation in Atlantic cod, in ICES Journal of Marine Science.
