Figure A5.

The effect of i.p. injections (0.5 μg/g) of estradiol (E2), estrone (E1), lumiestrone (LE), and control (charcoal-stripped peanut oil; 5 μL/g) on expression of liver estrogen receptor (ER)α in sexually in sexually inactive male goldfish using multiplex real-time PCR (8) after 24 h. Data (n = 6) are expressed as the mean (n = 6; ±SEM) fold change relative to the ERβ/β-actin ratios of the controls. Data were tested for normality and homoscedasity, and were transformed when appropriate prior to analysis by one-way ANOVA (treatment; p < 0.001) followed by Tukey’s post hoc test (S-Plus, v8.0). ^a,bMeans labeled with different superscripts are significantly different (p < 0.05). Note that ER β1 and ER β2 mRNAs were also measured in this PCR (not shown) but were not affected by treatment (p > 0.05). A subset (n = 3) of samples was screened by SYBR-Green-based PCR for vitellogenin-1 (VTG-1). VTGs are abundant phosphoproteins normally produced in the female liver that are released into circulation and accumulate in developing oocytes to provide nourishment for developing fish larvae. The gene is largely silent and undetectable in males unless they are exposed to estrogenic chemicals. No VTG-1 transcripts were amplified from control or LE-treated samples whereas it was detectable in all three of the samples from the E2 and E1-treatment groups. These data followed the general pattern for ERα and the average VTG-1/β-actin ratios for control, E2, E1, and LE were respectively 0 (not-detectable), 4.2, 5.9, and 0 (not-detectable).