Mariz Célio F, de Melo Alves Maria Karolaine, Magnuson Jason T, Castro Italo Braga, de Andrade Félix Augusto Silva, Zanardi-Lamardo Eliete, Medeiros Igor Dias, Carvalho Paulo S M
Department of Zoology, Federal University of Pernambuco, Recife-PE, 50670-901Brazil.
U.S. Geological Survey, Columbia Environmental Research Center, Columbia, Missouri, 65201United States.
Environ Toxicol Chem. 2025 Jul 22. doi: 10.1093/etojnl/vgaf184.
Proper development and inflation of the swim bladder is essential for swimming and foraging behavior in fish. To characterize the effects of the Brazilian oil spill that occurred between 2019 and 2020 to early life stage fish, the expression of genes involved in swim bladder development were targeted, with biochemical assays, morphology, and behavior assessed. The swim bladder was focused on due to recent findings of being a target of polycyclic aromatic hydrocarbons (PAHs) present in oil. Zebrafish (Danio rerio) were exposed to oil water accommodated fractions (WAFs) at concentrations measured following the spill, 1.12 to 71.8 total PAHs (μg-ΣPAHt L-1). Larvae exposed to 4.49 and 17.9 μg-ΣPAHt L-1 had a downregulation in the expression of swim bladder development genes, hb9, sox2, has2, and elovl1a, at 48 hours post fertilization (hpf). Downregulation in these genes was associated with a high frequency of uninflated swim bladders at 96 and 168 hpf, with uninflated swim bladders detected in 100% of 96 to 168 hpf larvae exposed to 35.9 and 71.8 μg-ΣPAHt L-1. SOD and CAT levels were inhibited in larvae exposed to 1.12 and 2.24 μg-ΣPAHt L-1, respectively. There was an increase in GST and GSH levels in exposed larvae. Average swimming speed and distance were reduced in larvae exposed to 1.12 μg-ΣPAHt L-1. This suggests that complex mixtures of PAHs from crude oil can inhibit the transcription of genes involved in swim bladder tissue development and proper swim-up behavior, which may have implications for the viability and success of developing larvae, impacting recruitment.
鱼鳔的正常发育和充气对于鱼类的游泳和觅食行为至关重要。为了描述2019年至2020年巴西石油泄漏对鱼类幼体阶段的影响，研究针对参与鱼鳔发育的基因表达进行了研究，并评估了生化分析、形态学和行为。由于最近发现鱼鳔是石油中多环芳烃（PAHs）的作用靶点，因此将重点放在鱼鳔上。斑马鱼（Danio rerio）暴露于按照泄漏后测量的浓度的油-水调和组分（WAFs）中，总PAHs浓度为1.12至71.8 μg-ΣPAHt L-1。受精后48小时（hpf），暴露于4.49和17.9 μg-ΣPAHt L-1的幼虫，其鱼鳔发育基因hb9、sox2、has2和elovl1a的表达下调。这些基因的下调与96和168 hpf时鱼鳔未充气的高频率相关，在暴露于35.9和71.8 μg-ΣPAHt L-1的96至168 hpf幼虫中，100%检测到鱼鳔未充气。暴露于1.12和2.24 μg-ΣPAHt L-1的幼虫中，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）水平分别受到抑制。暴露幼虫中的谷胱甘肽S-转移酶（GST）和谷胱甘肽（GSH）水平有所增加。暴露于1.12 μg-ΣPAHt L-1的幼虫的平均游泳速度和距离降低。这表明原油中的PAHs复杂混合物可抑制参与鱼鳔组织发育和正确上浮行为的基因转录，这可能对发育中幼虫的生存能力和成功发育产生影响，进而影响补充群体数量。
