Background: The dibutyl phthalate (DBP) is a member of the phthalate family and is widely used as a plasticizer in daily life and production. However, the influence of DBP on the vascular developmental remains unclear. Methods: In this study, we used zebrafish as a model organism to investigate the effects of DBP on vascular development in vivo. Death curves of zebrafish at different concentrations of DBP exposure and different times incubation were made firstly. Zebrafish embryos after fertilization for 5.5 h were exposed to different concentrations of DBP solution (0, 0.4, 0.8, 1.2 mg/L), the body length, yolk sac absorption area, mortality and heart rate of zebrafish were measured, and the number and area of sprouting of ventral vessels were quantified by transgenic fish system. Reactive oxygen species (ROS) in zebrafish embryos were observed by DCFH-DA staining. Super oxide dimutese (SOD) and catalase (CAT) were determined with ELISA kits. Results: We found that DBP increased the oxidative stress level of zebrafish exposed to DBP, and the genes related to vascular development also increased. Meanwhile, the activities of SOD and CAT were greatly decreased after DBP exposure. In the rescue experiment, we found that the antioxidant astaxanthin and the small molecule VEGF inhibitor ZM-306,416 can reverse the vascular dysplasia caused by DBP. Conclusions: DBP induced vascular developmental toxicity by enhancing oxidative stress levels, activating HIF pathway, and interfering with the expression of vascular development-related pathways in zebrafish, results in the abnormal development of the subintestinal vessels in zebrafish.
Abstract Clonal fishes are useful tools in biology and aquaculture studies due to their isogenicity. In Japanese flounder ( Paralichthys olivaceus ), a group of homozygous clones was created by inducing meiogynogenesis in eggs from a mitogynogenetic homozygous diploid. As the clones reached sexual maturity, meiogynogenesis was again induced in order to produce a 2 nd generation clonal group of Japanese flounder. After 3 months, there were 611 healthy, surviving individuals. Twenty-four microsatellite markers, that covered all the linkage groups of Japanese flounder, were used to identify the homozygosity of the 2 nd generation clones; no heterozygous locus was detected. This indicates that the production of a 2 nd generation clonal group of Japanese flounder was successful. Restriction-site DNA associated sequencing at the genomic level also confirmed the homozygosity and clonality of the 2 nd generation clonal group. Furthermore, these 2 nd generation clones had a small coefficient of variation for body shape indices at 210 days of age and showed a high degree of similarity in body characteristics among individuals. The successful production of 2 nd generation clones has laid the foundation for the large-scale production of clonal Japanese flounder.