Early-life glucocorticoids programme behaviour and metabolism in adulthood in zebrafish

1. View larger version:

   • In this window
   • In a new window

   • Download as PowerPoint Slide

   Figure 1

   Effects of embryonic treatment on larval growth and development. Results show the effects of dexamethasone, glucocorticoid receptor (GR) morpholino knockdown (GR Mo) and hypoxia treatment during 120h post fertilisation (hpf) on (A) chorion hatch rate, (B) head–trunk angle, (C) body length and (D) growth rate. For each treatment (●), results are compared with respective controls (○, vehicle, mismatched GR Mo or normoxia) by one-way ANOVA and Bonferroni post hoc analysis *P≤0.05, **P≤0.001. Results are mean±s.e.m. from n=3 experiments with 20 larvae/group for each experiment).
2. View larger version:

   • In this window
   • In a new window

   • Download as PowerPoint Slide

   Figure 2

   Effects of embryonic treatment on gross morphology of larvae. Images of whole larvae at 12h post fertilisation (hpf) (A, B, C and D), 18hpf (E, F, G and H) and 120hpf (I, J, K and L) show the effects of dexamethasone (B, F and J), hypoxia (C, G and K) and GR morpholino knockdown (GR Mo (D,h and L)) compared with untreated controls (A, E and I). Hypoxic larvae show reduced tail length and larger yolk sac and craniofacial immaturity. By contrast, dexamethasone-treated larvae show advanced eye development, somite patterning and yolk sac puckering. The delay in maturation in GR Mo is less prominent. The swim bladder appears less inflated in larvae with hypoxia and GR Mo treatment. Histological images of H&E-stained sections at two levels of magnification show typical examples of control (M), dexamethasone- (N), hypoxia- (O) and GR Mo-treated larvae at 120hpf (P). Features highlighted are swim bladder (SB), gut (G), yolk sac (YS), eye (E), heart (H) and brain (B). Analyses of images from 20 larvae/group were carried out in consultation with a veterinary pathologist.
3. View larger version:

   • In this window
   • In a new window

   • Download as PowerPoint Slide

   Figure 3

   Effects of embryonic treatments on movement, tactile responses, swimming and cortisol levels. Results show the effects of dexamethasone, GR morpholino knockdown (GR Mo) and hypoxia treatment on: (A) spontaneous twitch movement at 48h post fertilisation (hpf (n=3 experiments, 20 larvae per group)); (B) tactile responses of 96hpf larvae (n=5 experiments, 10 larvae per experiment); (C) Swim distance (mm/min) and (D) velocity during active swimming (mm/s) of 120hpf larvae averaged over a 5min period of observation (n=12 larvae); (E) developmental changes in whole larvae cortisol from 72 to 120hpf (n=3 experiments, 15 larvae pooled/group). Values are mean±s.e.m. and were analysed by one-way ANOVA and Bonferroni post hoc analysis.
4. View larger version:

   • In this window
   • In a new window

   • Download as PowerPoint Slide

   Figure 4

   Effect of embryonic treatment on adult body mass, blood glucose and hepatic pepck expression. The effects of embryonic pre-treatment with dexamethasone, hypoxia and GR Mo on body length (A), mass (B) and condition (C) are shown for adult fish at 84dpf. Representative images of adult control (D), dexamethasone (E), hypoxic (F) and GR Mo pre-treated (G) fish show no signs of gross abnormality. Effects of embryonic treatment on adult blood glucose (H) and hepatic pepck mRNA expression (I). All data are mean±s.e.m. compared against respective controls by Student’s t-test (*P ≤ 0.05, ***P ≤ 0.001). Data for A, B and C are n=10 fish, data forh are n=8 fish (mean of 2 readings per fish) and n=3 (5 pooled livers per sample) for mRNA expression. A full colour version of this figure is available at http://dx.doi.org/10.1530/JOE-15-0376.
5. View larger version:

   • In this window
   • In a new window

   • Download as PowerPoint Slide

   Figure 5

   Effect of embryonic treatment on adult behaviour and stress-induced changes in cortisol release. The effects of embryonic pre-treatment with dexamethasone, hypoxia and GR Mo on: (A) dive responses; (B) behaviour in an open-field test; (C) avoidance behaviour in response to a novel object and (D) swim velocity were analysed in adult fish. Values (mean±s.e.m., n=10) were analysed by one-way ANOVA and Bonferroni post hoc analysis, *P≤0.05, ***P≤0.001). Basal and stress-induced cortisol levels in swim water (E) from n=3 experiments (5 fish per tank per group) were analysed by one-way ANOVA and Bonferroni post hoc analysis, **P≤0.01.

• © 2016 Society for Endocrinology