Premium
Molecular cloning, tissue distribution and nutritional regulation of a Δ6‐fatty acyl desaturase‐like enzyme in large yellow croaker ( L arimichthys crocea )
Author(s) -
Zuo Rantao,
Mai Kangsen,
Xu Wei,
Dong Xiaojing,
Ai Qinghui
Publication year - 2016
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.12505
Subject(s) - biology , complementary dna , untranslated region , polyunsaturated fatty acid , biochemistry , molecular cloning , amino acid , enzyme , cloning (programming) , fatty acid , messenger rna , microbiology and biotechnology , gene , computer science , programming language
In this study, the full‐length c DNA of a Δ6‐fatty acyl desaturase‐like (Δ6‐Fad‐like) enzyme was first cloned from large yellow croaker, L armichthys crocea . The c DNA was 2049 bp, with a 107 bp 5′‐ UTR , a 604 bp 3′‐ UTR , and an ORF of 1338 that specified a protein of 445 amino acids. It contains two membrane‐spanning domains, three histidine‐rich regions and a cytochrome b 5 domain, which all align perfectly with the same domains located in other recently identified vertebrate Δ5 and Δ6 desaturases. Sequence comparison showed that the predicted protein revealed a high percentage identity (>70%) with Δ6 desaturases from other marine fish species. Tissue distribution analysis revealed that Δ6‐Fad‐like was expressed at highest level in brain, much lower level in liver and gill, and lowest level in spleen, heart, stomach and intestine. The hepatic m RNA levels of Δ6‐Fad‐like showed statistically negative relationship relative to increasing dietary n‐3 LC ‐ PUFA and DHA / EPA ( P < 0.05, R > 0.6). Transcription of Δ6‐Fad‐like in liver of fish fed diets with low and moderate level of n‐3 LC ‐ PUFA (0.15%, 0.60% and 0.98% dry diet) was significantly increased by more than 20‐fold than that with higher n‐3 LC ‐ PUFA (1.37%, 1.79% and 2.25% dry diet; P < 0.05). The transcriptional levels of Δ6‐Fad‐like in the liver of fish fed diets with the ratio of 0.61, 1.54 and 2.17 ( DHA / EPA ) were significantly up‐regulated by about 46‐fold, 4.8‐fold, and 1.2‐fold compared with that in the control group ( DHA / EPA = 3.88) respectively ( P < 0.05). This could contribute to better understanding the process of n‐3 LC ‐ PUFA biosynthesis in this fish species.