Bautista Naim M, Crespel Amélie, M Bautista Gil, Burggren Warren W
Department of Biological Sciences, University of North Texas, Denton, TX 76201, USA.
Department of Biology, University of Turku, 20500 Turku, Finland.
Sci Total Environ. 2023 Sep 20;892:164449. doi: 10.1016/j.scitotenv.2023.164449. Epub 2023 May 26.
Dietary crude oil exposure has detrimental morpho-physiological effects in fishes, including endocrine disruption. However, little is known about how it influences sex differentiation and its potential for skewing sex ratios of populations. Appropriate sex ratio is important for maintaining effective population size and structure. Deviations of these ratios can compromise population growth and maintenance and may induce changes in a species' evolutionary trajectory. We assessed the potential of dietary exposure to crude oil (6.5, 11.4, and 17.5 mg/kg food) to alter sex differentiation in the zebrafish (Danio rerio) (20-35 days post fertilization (dpf)) and subsequently skew the adult (90 dpf) sex ratio. Multiple health- and fitness-related phenotypic traits (i.e., body mass and length, condition factor, heart rate, oxygen consumption, and their capacity to cope with hypoxia) were also assessed to better understand the effects of dietary crude oil exposure. We showed that dietary exposure to crude oil during the process of sex differentiation skewed sex ratio towards males (up to 0.34:1 female to male ratio in the highest oil concentration). Remarkably, this effect occurred independently of affecting physiological variables and female gonad characteristics, thus highlighting just how subtle the effects of dietary crude oil exposure can be. Our results suggest that, although fish were in an apparently healthy state during experimentation, sex ratio was still impacted, potentially compromising the resilience of the population. Therefore, considering how complex chemical mixtures affect organisms at several levels (molecular-individual) in experimental designs is warranted to better understand the implications of the exposures and the hazards that populations face in the wild.
饮食中接触原油会对鱼类产生有害的形态生理影响，包括内分泌干扰。然而，对于它如何影响性别分化以及改变种群性别比例的可能性，我们知之甚少。合适的性别比例对于维持有效的种群规模和结构很重要。这些比例的偏差会损害种群的增长和维持，并可能导致物种进化轨迹的改变。我们评估了饮食中接触原油（6.5、11.4和17.5毫克/千克食物）对斑马鱼（Danio rerio）（受精后20 - 35天（dpf））性别分化的影响，以及随后对成年（90 dpf）性别比例的影响。还评估了多个与健康和适应性相关的表型特征（即体重和体长、条件因子、心率、耗氧量以及它们应对缺氧的能力），以更好地了解饮食中接触原油的影响。我们发现，在性别分化过程中饮食接触原油会使性别比例向雄性倾斜（在最高油浓度下，雌雄比例高达0.34:1）。值得注意的是，这种影响独立于对生理变量和雌性性腺特征的影响而发生，从而突出了饮食中接触原油的影响可能是多么微妙。我们的结果表明，尽管在实验过程中鱼看起来处于健康状态，但性别比例仍然受到影响，这可能会损害种群的恢复力。因此，在实验设计中考虑复杂的化学混合物如何在多个层面（分子 - 个体）影响生物体，对于更好地理解接触的影响以及种群在野外面临危险的情况是必要的。
