Endogenous biosynthesis of docosahexaenoic acid (DHA) regulates fish oocyte maturation by promoting pregnenolone production
Year: 2023
Type: article
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.
Source: 动物学研究
Authors: Yi Li, 中国科学院水生生物研究所种子设计创新研究院淡水生态与生物技术国家重点实验室, 湖北 武汉 430072, 中国, Xuehui Li, Ding Ye, Ru Zhang, Chengjie Liu, Mudan He, Houpeng Wang, Wei Hu, Yonghua Sun, 中国科学院大学现代农业科学学院, 北京 100049, 中国, 湖北洪山实验室, 湖北 武汉430070, 中国
Language: English
Subfield: Physiology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4386517818