PUBLICATION

Endogenous biosynthesis of docosahexaenoic acid (DHA) regulates fish oocyte maturation by promoting pregnenolone production

Authors
Li, Y., Li, X., Ye, D., Zhang, R., Liu, C., He, M., Wang, H., Hu, W., Sun, Y.
ID
ZDB-PUB-240111-8
Date
2024
Source
Zoological research   45: 176188176-188 (Journal)
Registered Authors
He, Mudan, Hu, Wei, Sun, Yonghua, Ye, Ding
Keywords
Docosahexaenoic acid, Microtubule, Oocyte maturation, Oocyte quality, Pregnenolone
MeSH Terms
  • Animals
  • Cholesterol Side-Chain Cleavage Enzyme
  • Docosahexaenoic Acids*
  • Humans
  • Oocytes
  • Oogenesis/genetics
  • Zebrafish*
PubMed
38199972 Full text @ Zool Res
Abstract
Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly docosahexaenoic acid (22:6n-3, DHA), play crucial roles in the reproductive health of vertebrates, including humans. Nevertheless, the underlying mechanism related to this phenomenon remains largely unknown. In this study, we employed two zebrafish genetic models, i.e., elovl2-/- mutant as an endogenous DHA-deficient model and fat1 (omega-3 desaturase encoding gene) transgenic zebrafish as an endogenous DHA-rich model, to investigate the effects of DHA on oocyte maturation and quality. Results show that the elovl2-/- mutants had much lower fecundity and poorer oocyte quality than the wild-type controls, while the fat1 zebrafish had higher fecundity and better oocyte quality than wild-type controls. DHA deficiency in elovl2-/- embryos led to defects in egg activation, poor microtubule stability, and reduced pregnenolone levels. Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1, which encodes the cholesterol side-chain cleavage enzyme, thereby stabilizing microtubule assembly during oogenesis. In turn, the hypothalamic-pituitary-gonadal axis was enhanced by DHA. In conclusion, using two unique genetic models, our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping