Different Life‐Stage Exposure to Hexafluoropropylene Oxide Trimer Acid Induces Reproductive Toxicity in Adult Zebrafish (Danio rerio).

As a novel alternative to perfluorooctanoic acid (PFOA), hexafluoropropylene oxide trimer acid (HFPO‐TA) has been widely used and has caused ubiquitous water pollution. However, its adverse effects on aquatic organisms are still not well known. In the present study, zebrafish at different life stages were exposed to 0, 5, 50, and 100 μg/L of HFPO‐TA for 21 days to investigate reproductive toxicity in zebrafish. The results showed that HFPO‐TA exposure significantly inhibited growth and induced reproductive toxicity in zebrafish, including a decrease of the condition factor, gonadosomatic index, and the average number of eggs. Histological section observation revealed that percentages of mature oocytes and spermatozoa were reduced, while those of primary oocytes and spermatocytes increased. In addition, exposure to HFPO‐TA at three stages induced a significant decrease in the hatching rate, while the heart rate and normal growth rate of F1 offspring were only significantly inhibited for the exposure from fertilization to 21 days postfertilization (dpf). Compared with the exposure from 42 to 63 dpf, the reproductive toxicity induced by HFPO‐TA was more significant for the exposure from fertilization to 21 dpf and from 21 to 42 dpf. Expression of the genes for cytochrome P450 A1A, vitellogenin 1, estrogen receptor alpha, and estrogen receptor 2b was significantly up‐regulated in most cases after exposure to HFPO‐TA, suggesting that HFPO‐TA exhibited an estrogen effect similar to PFOA. Therefore, HFPO‐TA might disturb the balance of sex steroid hormones and consequently induce reproductive toxicity in zebrafish. Taken together, the results demonstrate that exposure to HFPO‐TA at different life stages could induce reproductive toxicity in zebrafish. However, the underlying mechanisms deserve further investigation. Environ Toxicol Chem 2023;42:2490–2500. © 2023 SETAC [ABSTRACT FROM AUTHOR]