Gene expression in the telencephalon of adult wildtype (A++B++) and cyp19a1b^-/- mutant (A++B–) female zebrafish in the morning (10h00) and afternoon (14h00). The abundance of mRNAs (copies/µL) for all genes measured was normalized by tata-binding protein levels within the sample and data are plotted as fold change relative to the wildtype female levels at 10h00. Parametric data were analyzed by Two-Way ANOVA tests followed by Tukey’s multiple comparisons tests and individual values are plotted with bars representing mean values (A, B, D, F, G), whilst non-parametric data were analyzed using multiple Mann-Whitney U tests with a Holm-Šídák correction for multiple comparisons and plotted as individual points with bars representing median values (C, E). Error bars are not displayed for clarity. Significant main effects of time (horizontal bars) and genotype (arrows) are indicated by asterisks (** p<0.01; *** p<0.001). When there is a statistically significant interaction effect, means with different letters a-b represent statistically significant differences (p<0.05).

Gene expression in the hypothalamus of adult wildtype (A++B++) and cyp19a1b^-/- mutant (A++B–) female zebrafish in the morning (10h00) and afternoon (14h00). The abundance of mRNAs (copies/µL) for all genes measured were normalized by tata-binding protein levels within the sample and data are plotted as fold change relative to the wildtype female levels at 10h00. Parametric data were analyzed by Two-Way ANOVA tests followed by Tukey’s multiple comparisons tests and individual values are plotted with bars representing mean values (A–E, G), whilst non-parametric data were analyzed using multiple Mann-Whitney U tests with a Holm-Šídák correction for multiple comparisons and plotted as individual points with bars representing median values (F). Error bars are not displayed for clarity. Significant main effects of time (horizontal bars) and genotype (arrows) are indicated by asterisks (* p<0.05; ** p<0.01). When there is a statistically significant interaction effect, means with different letters a-b represent statistically significant differences (p<0.05).

Estradiol (E2) levels in the brains of adult wildtype (A++B++) and cyp19a1b^-/- mutant (A++B–) female zebrafish in the morning (10h00) and afternoon (14h00). Data were analyzed using a Two-Way ANOVA followed by Tukey’s multiple comparisons tests. Significant main effects of time (**, p=0.0072) and genotype (*** with arrow; p=0.0003) are indicated. There was no significant interaction effect. Data are plotted as means + standard error of the mean (n=4-5 per group).

Time to first oviposition event during zebrafish pairwise mating trials with female cyp19a1b^-/- mutant fish intraperitoneally injected with nonapeptides and mixed nonapeptides with receptor antagonists (n=15 per group). Significant differences were assessed using a Kruskal-Wallis test followed by a Dunn’s multiple comparisons test. Individual data points are displayed with red bars representing median values. Different letters a-b represent statistically significant differences. Statistical significance is defined at p<0.05.

Arginine vasopressin (Avp) immunolabelling in pre-adsorption tests with Avp and Oxytocin (Oxt) in a transverse section of a female wildtype zebrafish preoptic area. The confocal images show Avp-immunopositive cell bodies surrounding the diencephalic ventricle (A). No Avp-immunopositive neurons were present in sections pre-adsorbed with Avp (B). Avp immunolabelling was unaffected in sections pre-adsorbed with Oxt (C). Scale bar=20 µm.

Double immunofluorescence against Cyp19a1b (green) and Arginine vasopressin (Avp; red) in a female Tg(cyp19a1b-GFP) zebrafish anterior preoptic area. In this transverse brain section, Cyp19a1b-positive radial glial cells fibres lining the peripheral layer of the ventral telencephalon (A) surround an Avp-immunopositive parvocellular cell body (B). The nuclear stain Hoescht (blue) is also shown (C). Single slice scanning view of the boxed area in panel D shows Cyp19a1b-positive fibres in contact with the Avp-immunopositive cell body (E). Scale bar=20 µm.

Double immunofluorescence against Cyp19a1b (green) and Arginine vasopressin (Avp; red) in a female Tg(cyp19a1b-GFP) zebrafish posterior preoptic area. In this transverse brain section, Cyp19a1b-positive radial glial cell fibres (A, F) surround Avp-immunoreactive magnocellular (B) and gigantocellular (G) cell bodies. The nuclear stain Hoescht (blue) is also shown (C, H). Single slice scanning view of the boxed areas in (D, I) show Cyp19a1b-positive fibres in contact with the Avp-immunopositive cell bodies (E, J). Scale bar=20 µm.