Figure 5

Figure 5

Gametogenesis analysis of knockout and WT zebrafish undergoing fed and fasted conditions. Percentage of oocytes at pre-vitellogenic, early-mid vitellogenic, and late/fully mature stages of WT and gnrh2^−/− ovaries after fed and fasted conditions demonstrate significantly fewer late/fully mature oocytes in gnrh2^−/− in fasted conditions (a). Histological sections of ovaries with labelled germinal vesicles (GV), cortical alveoli (ca), pre-vitellogenic oocytes (PV), and primary-growth follicles (PG), demonstrating fully mature oocytes (yellow star *) present in fed and fasted WT ovaries, but only present in fed gnrh2^−/− ovaries (b). GSI % quantification indicates reduced GSI in gnrh2^−/− undergoing fed and fasted conditions (c). Histological sections of testes demonstrate mature spermatozoa ▲ in fed and fasted WT and gnrh2^−/− males (d) with GSI % quantification indicating no difference in genotypes undergoing fed and fasted conditions (e). All data expressed as means ± S.E.M, n = 10 gonads per group, *P < 0.05, **P < 0.01, different letters indicate significant differences (P < 0.05) from each other (statistical comparisons made only between similarly-staged oocytes which are characterized by quote marks: no mark = pre-vitellogenic, ‘ = early-mid vitellogenic, ‘’ = late/fully mature).