AUTHOR=Lin Zhideng , Wu Zhouyu , Huang Chaoyang , Lin Huangbin , Zhang Mingyao , Chen Mingfeng , Han Kunhuang , Huang Weiqing , Ruan Shaojiang 

TITLE=Cloning and expression characterization of elongation of very long-chain fatty acids protein 6 (elovl6) with dietary fatty acids, ambient salinity and starvation stress in Scylla paramamosain

JOURNAL=Frontiers in Physiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1221205

DOI=10.3389/fphys.2023.1221205

ISSN=1664-042X

ABSTRACT=<p><bold>Introduction:</bold> Elongation of very long-chain fatty acids protein 6 (ELOVL6) played crucial roles in regulating energy expenditure and fatty acid metabolism. Many studies have performed to investigate the physiological roles and regulatory mechanisms of <italic>elovl6</italic> in fish and animals, while few studies were reported in crustaceans.</p><p><bold>Methods:</bold> Here we reported on the molecular cloning, tissue distribution and expression profiles in response to dietary fatty acids, ambient salinity and starvation stress in <italic>Scylla paramamosain</italic> by using rapid amplification of cDNA ends (RACE) and quantitative real-time PCR.</p><p><bold>Results:</bold> Three <italic>elovl6</italic> isoforms (named <italic>elovl6a, elovl6b</italic> and <italic>elovl6c</italic>) were isolated from <italic>S. paramamosain</italic> in the present study. The complete sequence of <italic>elovl6a</italic> was 1345 bp, the full-length sequence of <italic>elovl6b</italic> was 1419 bp, and the obtained <italic>elovl6c</italic> sequence was 1375 bp in full length. The <italic>elovl6a, elovl6b</italic> and <italic>elovl6c</italic> encoded 287, 329 and 301 amino acids respectively, and exhibited the typical structural features of ELOVL protein family members. Phylogenetic analysis showed that the ELOVL6a from <italic>S. paramamosain</italic> clustered most closely to ELOVL6 from <italic>Portunus trituberculatus</italic> and <italic>Eriocheir sinensis</italic>, while the ELOVL6b and ELOVL6c from <italic>S. paramamosain</italic> gathered alone into a single branch. Quantitative real-time PCR exhibited that the relatively abundant expression of <italic>elovl6b</italic> was observed in intestine and stomach, and the <italic>elovl6a</italic> and <italic>elovl6c</italic> were highly expressed in hepatopancreas. In addition, studies found that replacing fish oil with soybean oil could significantly increase the transcriptional levels of three <italic>elovl6</italic> in hepatopancreas of <italic>S. paramamosain</italic>, and the expression of <italic>elovl6a</italic> and <italic>elovl6c</italic> in hepatopancreas were more sensitive to dietary fatty acids than the <italic>elovl6b</italic>. Compared with the normal sea water group (27‰), the expression of sterol-regulatory element binding protein1c <italic>(srebp-1), elovl6a, elovl6b</italic> and <italic>elovl6c</italic> were upregulated in the low salinity groups, particularly in 7‰. On the contrary, the starvation stress suppressed the expression of <italic>srebp-1, elovl6a, elovl6b</italic> and <italic>elovl6c</italic>.</p><p><bold>Discussion:</bold> These results may contribute to understand the functions of <italic>elovl6</italic> in fatty acid synthesis and regulatory mechanisms in crustaceans.</p>