Related Experiment Video
Updated: Apr 4, 2026
Author Spotlight: Enhanced Method for Isolating Pure Zebrafish Stage I Oocytes
Published on: July 26, 2024
Morphological and molecular effects of cortisol and ACTH on zebrafish stage I and II follicles
Maria Lígia Sousa1, Francisco Figueiredo2, Catarina Pinheiro2
1CIIMAR - Interdisciplinary Center of Marine and Environmental ResearchCIMAR Associated Laboratory, U. Porto - University of Porto, Rua dos Bragas 289, 4050-123 Porto, PortugalICBAS - Institute of Biomedical Sciences Abel SalazarUPorto - University of Porto, Rua de Jorge Viterbo Ferreira n° 228, 4050-313 Porto, PortugalISCS-N - Superior Institute of Health Sciences-NorthCESPU - Cooperative Higher Education, Polytechnic and University, Rua Central da Gandra 1317, 4585-116 Gandra, Portugal CIIMAR - Interdisciplinary Center of Marine and Environmental ResearchCIMAR Associated Laboratory, U. Porto - University of Porto, Rua dos Bragas 289, 4050-123 Porto, PortugalICBAS - Institute of Biomedical Sciences Abel SalazarUPorto - University of Porto, Rua de Jorge Viterbo Ferreira n° 228, 4050-313 Porto, PortugalISCS-N - Superior Institute of Health Sciences-NorthCESPU - Cooperative Higher Education, Polytechnic and University, Rua Central da Gandra 1317, 4585-116 Gandra, Portugal.
Abstract:
Oogenesis in zebrafish (Danio rerio) is controlled by the hypothalamus-pituitary-gonadal axis and reproductive hormones. In addition, an interference of stress hormones is known with reproductive biology. In the presented work, we aimed to explore the hypothesis that cortisol (Cort) and ACTH may affect early oogenesis in zebrafish, given the presence of the specific receptors for glucocorticoids and ACTH in the zebrafish ovary. Follicles at stages I and II were exposed in vitro to 1 μM Cort and ACTH for 48 h, then ultrastructural and molecular effects were analyzed. The comet assay demonstrated increased tail moments for Cort and ACTH treatment indicative of DNA damage. The mRNA expression of apoptotic genes (bax, bcl-2) was not altered by both treatments, but Cort increased significantly the expression of the ACTH receptor (mc2r). Cort stimulated the presence of the endoplasmic reticulum, predominantly at stage II, while ACTH induced a strong vacuolization. Viability of oocytes was not affected by both treatments and fluorescent staining (monodansylcadaverine/acridine orange) indicated a reduced quantity of autophagosomes for ACTH, and lower presence of nucleic acids in ooplasm for Cort and ACTH. Concluding, different responses were observed for stress hormones on early stages of zebrafish oocytes, which suggest a role for both hormones in the stress-mediated adverse effects on female gametogenesis.
