Elovl2 But Not Elovl5 Is Essential for the Biosynthesis of Docosahexaenoic Acid (DHA) in Zebrafish: Insight from a Compa
- PDF / 2,367,098 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 9 Downloads / 187 Views
SHORT COMMUNICATION
Elovl2 But Not Elovl5 Is Essential for the Biosynthesis of Docosahexaenoic Acid (DHA) in Zebrafish: Insight from a Comparative Gene Knockout Study Chengjie Liu 1,2 & Ding Ye 1,2
&
Houpeng Wang 1 & Mudan He 1,2 & Yonghua Sun 1,2
Received: 19 May 2020 / Accepted: 23 August 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Teleost fish can synthesize one of the major omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), docosahexaenoic acid (DHA, 22:6n-3), from dietary α-linolenic acid (ALA; 18:3n-3), via elongase of very long– chain fatty acid (Elovl) and fatty acid desaturase (Fads). However, it remains unclear which elongase is primarily responsible for the endogenous synthesis of DHA. Here, in this study, the knockout models of the two major elongases, Elovl2 and Elovl5, were generated by CRISPR/Cas9 approach in zebrafish and comparatively analyzed. The homozygous mutants were validated by Sanger sequencing, mutation-mediated PCR, and whole-mount in situ hybridization analysis of the endogenous target genes. Compared with wild-type (WT) counterparts, the content of DHA was significantly reduced by 67.1% (P < 0.05) in the adult liver and by 91.7% (P < 0.01) in the embryo at 3day post-fertilization (dpf) of the elovl2 mutant, but not of the elovl5 mutant. Further study revealed that elovl2 and fads2 was upregulated by 9.9-fold (P < 0.01) and 9.7-fold (P < 0.01) in the elovl5 mutant, and elovl5 and fads2 were upregulated by 15.1-fold (P < 0.01) and 21.5-fold (P < 0.01) in the elovl2 mutant. Our study indicates that although both Elovl2 and Elovl5 have the elongase activity toward C20, the upregulation of elovl2 could completely replace the genetic depletion of elovl5, but upregulation of elovl5 could not compensate the endogenous deficiency of elovl2 in mediating DHA synthesis. In conclusion, the endogenous synthesis of DHA in is mediated by Elovl2 but not Elovl5 in zebrafish and a DHA-deficient genetic model of zebrafish has been generated. Keywords Elovl2 . Elovl5 . Docosahexaenoic acid . Zebrafish
Introduction Long-chain polyunsaturated fatty acids (LC-PUFAs), which possess 20 or more carbon atoms and contain two or more double bonds in their carbon chains, e.g., docosahexaenoic acid (DHA, 22:6n-3), are essential nutrients for neural development and health (Heird and Lapillonne 2005). During the biosynthesis of LC-PUFAs,
* Yonghua Sun [email protected] 1
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan 430072, China
2
College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
fatty acid desaturase (Fads) and elongase of very long– chain fatty acid (Elovl) are critical enzymes for desaturation and elongation in LC-PUFA synthesis from dietary essential fatty acids, α-linolenic acid (ALA, 18:3n-3), and linoleic acid (LA, 18:2n-6) (Monroig et al. 2013; Guillou et al. 2010). The enzyme activi
Data Loading...
