|ZFIN ID: ZDB-PUB-201203-2|
Knockout of the Glucocorticoid Receptor Impairs Reproduction in Female Zebrafish
Maradonna, F., Gioacchini, G., Notarstefano, V., Fontana, C.M., Citton, F., Dalla Valle, L., Giorgini, E., Carnevali, O.
|Source:||International Journal of Molecular Sciences 21(23): (Journal)|
|Registered Authors:||Carnevali, Oliana, Citton, Filippo, Dalla Valle, Luisa, Fontana, Camila Maria|
|Keywords:||Danio rerio, Fourier transform infrared imaging spectroscopy, glucocorticoids, gr mutants, oocyte maturation, vitellogenesis|
|PubMed:||33260663 Full text @ Int. J. Mol. Sci.|
Maradonna, F., Gioacchini, G., Notarstefano, V., Fontana, C.M., Citton, F., Dalla Valle, L., Giorgini, E., Carnevali, O. (2020) Knockout of the Glucocorticoid Receptor Impairs Reproduction in Female Zebrafish. International Journal of Molecular Sciences. 21(23):.
ABSTRACTThe pleiotropic effects of glucocorticoids in metabolic, developmental, immune and stress response processes have been extensively investigated; conversely, their roles in reproduction are still less documented. It is well known that stress or long-lasting therapies can cause a strong increase in these hormones, negatively affecting reproduction. Moreover, the need of glucocorticoid (GC) homeostatic levels is highlighted by the reduced fertility reported in the zebrafish glucocorticoid receptor mutant (nr3c1ia30/ia30) line (hereafter named gr-/-). Starting from such evidence, in this study, we have investigated the role of glucocorticoid receptor (Gr) in the reproduction of female zebrafish. Key signals orchestrating the reproductive process at the brain, liver, and ovarian levels were analyzed using a multidisciplinary approach. An impairment of the kiss-GnRH system was observed at the central level in (gr-/-) mutants as compared to wild-type (wt) females while, in the liver, vitellogenin (vtg) mRNA transcription was not affected. Changes were instead observed in the ovary, particularly in maturing and fully grown follicles (classes III and IV), as documented by the mRNA levels of signals involved in oocyte maturation and ovulation. Follicles isolated from gr-/- females displayed a decreased level of signals involved in the acquisition of competence and maturation, causing a reduction in ovulation with respect to wt females. Fourier transform infrared imaging (FTIRI) analysis of gr-/- follicle cytoplasm showed major changes in macromolecule abundance and distribution with a clear alteration of oocyte composition. Finally, differences in the molecular structure of the zona radiata layer of gr-/- follicles are likely to contribute to the reduced fertilization rate observed in mutants.