Fig. 4

The KEGG enrichment pathways of the DEGs enriched in top 20 KEGG terms in eyes of larvae for 5-day exposure. (A-C) The top 20 enriched KEGG pathways of DEGs in 1, 10 and 100 μg/L BPA group compared with the vacuity control groups (DMSO), respectively. (D-F) KEGG enrichment on DEGs -Net plot in 1, 10, and 100 μg/L BPA group in comparison with the control. Note: The lines of different colors represent varied KEGG pathways enriched in different BPA concentration, and the colors of the lines represent multiple differences. The larger the area enclosed by the lines, the more genes are enriched in the KEGG pathway. (G) Schematic diagram of the interaction of key DEGs in Phototransduction pathway. Note: Schematic diagram depicts the Phototransduction pathway in larval zebrafish and 23 key genes measured in the present work. Note: Schematic representation of and Ca2+-regulated deactivation processes and Phototransduction pathway (the optical transduction process). Photoreceptors absorb light signals to activate R (the phosphorylated R*). Then R* triggers the exchange of the GTP for the GDP under the action of Gt. Gt-α-GTP binds to the PDE to stimulate PDE, then the free cGMP was hydrolyzed. On the other hand, CNGC allows Ca2+ and Na+ flow in darkness, however, CNGC channels are shut off by the decreased cGMP during illumination. On the contrary, NCKX channels are not influenced under luminous environment, causing a decrease of Ca2+ concentration in photoreceptors. Meanwhile, Rcv modulates the process of R* phosphorylation via GRK in a Ca2+-dependent manner. Finally, the R* is deactivated with Arr. R* , light-activated visual pigment (active); R, visual pigment (inactive); Gα-β-γ, transducin α, β and γ subunits; GRK, G protein-coupled receptor kinase; cGMP, cyclic guanosine monophosphate; PDE, phosphodiesterase (inactive); CNGC, cyclic nucleotide–gated ion channel; NCKX, Na+/Ca2+, K+ exchanger; P, phosphorylation; Rcv, Recoverin; Arr, arrestin; GC, guanylate cyclase; Gt, transducin protein; GCAP, guanylate cyclase activating protein. (H) The expression of key DEGs in Phototransduction pathway. (I) The expression of key DEGs related to cell apoptosis. Note: The boxes with red and blue colors depict relative up- and down-regulated expression compared with vacuity control groups. DEGs and samples are clustered by similarity, and samples from each BPA- exposed group cluster together showing differential gene expression of genes between two groups.