A study on the mechanism of Indium phosphide/zinc sulfide core/shell quantum dots influencing embryo incubation of rare minnow (Gobiocypris rarus)

Quantum dots (QDs) inhibit fish hatching, but the mechanism is still unclear. In this study, the effect of Indium phosphide/zinc sulfide quantum dots (InP/ZnS QDs) on the embryo incubation of rare minnow was investigated. Five experimental concentration groups were set up according to the preliminary experimental results, which were 0, 50, 100, 200 and 400 nM. A direct exposure method was adopted to expose embryos to InP/ZnS QDs solution. The results showed that InP/ZnS QDs significantly inhibited the embryo hatching rate, delayed embryo emergence, affected the expression of genes associated with hatching gland cells and hatching enzymes. InP/ZnS QDs also destroy the structure of the embryo chorion. In addition, QDs can cause oxidative stress in embryos. Transcriptional sequencing analysis showed that InP/ZnS QDs InP/ZnS QDs may have induced the production of a hypoxic environment and triggered induce abnormal cardiac muscle contraction, inflammatory response and apoptosis process in embryos. In conclusion, QDs influences embryo hatchability largely through egg chorion mediation.