Fig. 4: rbfox1 mutants undergo adaptive mechanisms and allostatic overload during development.

Expression levels of A) HPI axis genes corticotropin releasing hormone b (crhb), mineral corticoid receptor (mr) and glucocorticoid receptor (gr) and of B) bdnf and trkb2 truncated/full-length (TK-/TK+) (common primers) in adult zebrafish brain (rbfox1^+/+ and rbfox1^19del/19del) in normal resting conditions and after exposure to a stressor (novel tank diving). C) Expression levels of the trkb2 TK+ and TK- in adult zebrafish brain (rbfox1^+/+ and rbfox1^19del/19del) after exposure to a stressor. trkb2 expression is shown in a stacked bar format, where the directly measured TK+ (long form) is shown as the lower portion and the inferred TK- (short form) is shown on top. D) Expression levels of proliferating cell nuclear antigen (pcna) in 5 days post fertilisation zebrafish larvae and adult zebrafish brain (rbfox1^+/+ and rbfox1^19del/19del) in normal resting conditions. E) Fertility rate and F) survival rate of rbfox1^+/+ and rbfox1^19del/19del. Each green dot/pink triangle in A-B) represents a single adult rbfox1^+/+ or rbfox1^19del/19del brain under resting physiological conditions respectively, while yellow dots/triangles represent rbfox1^+/+ or rbfox1^19del/19del brain after stress exposure respectively. In B) each green dot/pink triangle represents single adult rbfox1^+/+ or rbfox1^19del/19del brain after stress exposure respectively. In D) for larvae each green dot/pink triangle represents a pool of rbfox1^+/+ or rbfox1^19del/19del 15 larval heads (eyes and jaw removed) respectively; for adults each green dot/pink triangle represents a single adult rbfox1^+/+ or rbfox1^19del/19del brain respectively. In E) each dot/triangle represents average fertility of 3–5 trios (1 male and 2 females) assessed over 2–3 petri dish (50 embryos per dish) per trio. Each trio belonged to a different tank (for each genotype for each batch) to avoid tank effect). In F) each dot/triangle represents the percentage of survival of a single fish stock comprising 50 larvae. For qPCR experiments, reference genes were actin – β 2 (actb2) and ribosomal protein L13a (rpl13a). Where indicated, we used Log₁₀ transformation to normalize the data facilitating a clearer visualization of trends within the dataset. All larvae employed were progeny of rbfox1^+/19del in-cross and were genotyped after experiments and prior to data analysis. In all graphs: bars represent standard error of the mean (SEM); * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001.