Molecular cloning, tissue distribution and nutritional regulation of a fatty acylelovl5-likeelongase in large yellow croaker,Larimichthys crocea

Abstract

In this study, the full‐length cDNA of fatty acyl elovl5‐like elongase was first cloned from large yellow croaker, Larimichthys crocea. The cDNA of elovl5‐like was 1551 bp, including a 5′‐terminal untranslated region (UTR) of 120 bp, a 3′‐terminal UTR of 546 bp and an open reading frame (ORF) of 885 bp encoding a polypeptide of 294 amino acid residues. Sequence comparison showed that the predicted protein revealed a high percentage identity (>80%) with Elovl5 from other marine fish species. Tissue distribution analysis revealed that the elovl5‐like was expressed highly in liver, brain and gill, and at much lower levels in stomach, intestine, heart and spleen. Quantity polymerase chain reaction showed that hepatic elovl5‐like transcription decreased significantly with the increase in dietary n‐3LC‐PUFA (P < 0.05). The mRNA levels of elovl5‐like in the liver of fish fed diets with 0.15%, 0.60% and 0.98% n‐3LC‐PUFA were up‐regulated by 1.77‐fold, 1.41‐fold and 1.41‐fold than that with 2.25% n‐3LC‐PUFA respectively. No significant differences were observed in the hepatic mRNA levels of elovl5‐like in response to the increased ratio of dietary DHA/EPA (P > 0.05). These results demonstrate for the first time the presence and nutritional modulation of elovl5‐like cDNA in large yellow croaker. This could contribute to better understanding the process of n‐3LC‐PUFA biosynthesis in this fish species.

Molecular Characterization, Tissue Distribution and Differential Nutritional Regulation of Three n-3 LC-PUFA Biosynthesis-Related Genes in Hybrid Grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)

“…As alternative oil sources lacking in LC-PUFA are gradually being used in the diet, it is essential to clarify the patterns of dietary fatty acids in regulating genes encoding desaturases and elongases in farmed fish. As the liver serves as the primary site for FA metabolism, including de novo synthesis of FA, we evaluated the gene expression of elovl5, elovl8 and fads2 in the liver of hybrid groupers, and they were down-regulated by higher dietary n-3 LC-PUFA levels, which was consistent with the findings in the orange-spotted grouper [28,29,44] and other fish species such as the large yellow croaker [46]. These observations reflect the negative feedback regulation of the LC-PUFA synthetic pathway.…”

Gene cloning, expression pattern, and response to dietary total lipids and phospholipids of hormone-sensitive lipase (HSL) in the Oriental river prawn Macrobrachium nipponens

“…Lipids are the predominant energy source for animals; fatty acids stored in the form of triacylglycerol and phospholipids are the main energy source for growth, survival and developmental and reproductive processes of aquatic species (Ouellet et al, 1992;Arslan et al, 2010;Zuo et al, 2016;Kabeya et al, 2017). Phospholipids promote the emulsi cation of the lipids to improve absorption (Kontara et al, 1998;Caballero et al, 2006), decrease lipid accumulation in the liver (Cai et al, 2017), and improve stress resistance of shrimp (Ju et al, 2011) apparently by facilitating the decomposition of triglycerides in adipose tissue to release free fatty acids (Strokova and Smirnova, 1976).…”