1,3-二苯胍对斑马鱼早期生命阶段的影响

Effects of 1,3-diphenyl Guanidine on Early Life Stages of Zebrafish

1,3-二苯胍(1,3-diphenyl guanidine,DPG)是橡胶生产过程中添加的硫化促进剂,在水环境中广泛存在。然而作为水环境中的一种污染物,目前DPG对水生生物的毒性及其机制的研究极为匮乏。为了研究DPG对水生生物的生殖发育毒性及潜在机制,选择水生模式生物斑马鱼(Danio rerio)作为受试生物。将斑马鱼胚胎分别暴露于浓度为30、100和300μg·L^(-1)的DPG溶液中120 h,通过转录组测序、基因表达水平定量分析及性激素水平测定(雌二醇和睾酮)来探究其对斑马鱼早期生命阶段的生殖发育毒性及机制。转录组测序结果表明,DPG暴露可以显著影响与精卵识别及生殖细胞发育相关的生物学过程。DPG暴露使类固醇合成通路相关基因(cyp11a1、cyp17a1、cyp19a1a、hsd17b1、ar)的转录表达显著上调。激素结果表明DPG暴露导致斑马鱼仔鱼体内雌二醇水平显著升高。以上研究结果表明,在分子水平上,DPG能够影响斑马鱼胚胎及仔鱼的发育,但是在个体水平上仍然缺乏直接的证据揭示DPG暴露对斑马鱼生殖和胚胎发育的不良结局。本研究为DPG对水生生物的毒性研究奠定了一定的基础,并为轮胎磨损颗粒的毒性研究提供了新的线索。

1,3-diphenyl guanidine(DPG)is a vulcanization accelerator added during rubber production and has been widely detected in aquatic environments.However,the information on the aquatic toxicity and the toxic mechanism of this pollutant is still very limited.To study the reproductive and developmental toxicity as well as the underlying mechanisms of DPG in aquatic organisms,we employed zebrafish(Danio rerio)as the model and exposed zebrafish embryos to 30,100 and 300μg·L^(-1) of DPG solution for 120 h.After that,transcriptome sequencing,gene expression analysis and sex hormone determination(estradiol and testosterone)were performed.RNA sequencing data revealed that DPG significantly affected biological processes related to sperm-egg recognition and germ cell development.In addition,qPCR analysis demonstrated that DPG also stimulated the expression of a few genes closely related to the steroid biosynthesis pathway,including cyp11a1,cyp17a1,cyp19a1a,hsd17b1,and ar,in zebrafish larvae.ELISA analysis showed elevated estradiol levels in zebrafish larvae upon DPG exposure.Our results suggest that,at the molecular level,DPG is capable of affecting the development of zebrafish embryo and larvae;however,there is still a lack of direct evidence at the individual level showing the adverse outcome of DPG exposure on the reproduction and embryo development.This study lays the foundation for the study on the aquatic toxicity of DPG and provides new clues of the potential influence of tire wear particles.