Figure 4

The expression of gill VILL was induced by the decreasing environmental salinities. (A) The mRNA levels of Odvill in gills of the brackish medaka acclimated to SW, 50% SW, or FW (n=6 for all groups). The mRNA abundance increased with decreasing environmental salinity. (B) Representative immunoblot of VILL from gills of the brackish medaka acclimated to FW, 50% SW, or SW, detected with the specific polyclonal antibody. Two immunoreactive bands were found at 100 kDa and 90 kDa. The sum of relative intensities of the two immunoreactive bands of branchial VILL protein was analyzed and compared among the three salinity groups (n=6 for each) to show that the amount of VILL significantly increased with decreasing environmental salinity. (C) Dynamic expression of Odvill mRNA in gills of the brackish medaka transferred from SW to FW. Odvill mRNA were significantly increased to approximately 5-fold 1 day post-transfer and increased to approximately 17-fold 2 days post-transfer compared to baseline (0 day; SW) (n=5 for all groups). (D) Representative immunoblot of VILL in gills of the brackish medaka after transfer from SW to FW, as detected by the specific antibody to VILL. Dynamic expression of the VILL protein in gills of the brackish medaka transferred from SW to FW. The abundances of VILL increased gradually in the first 2 days after transfer (3-fold) and increased to 5-fold after 4 days compared to baseline (0 day; SW) (n=5 for all groups). β-actin was used as the loading control. Different letters indicated significant differences (p < 0.05) using Tukey’s multiple comparison test following a one-way ANOVA. The values are means ± S.E.M.