Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China.
Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China.
Gene. 2019 Jul 15;705:133-141. doi: 10.1016/j.gene.2019.04.043. Epub 2019 Apr 17.
Fatty acid desaturases (Fads) are a key enzyme in the process of biosynthesis of highly unsaturated fatty acids (HUFAs). In this study, we cloned the full-length sequence of the SiFad1 gene (SiFad1) and analyzed its expression profiles during different developmental stages and in different tissues of Strongylocentrotus intermedius. The full-length cDNA of SiFad1 is composed of 1086 bp, with a putative open reading frame of 885 bp encoding a polypeptide of 294 amino acid (AA) residues. The predicted molecular mass of SiFad1 is 34.67 kDa and its theoretical pI is 8.41. The presence of conserved motifs including three histidine boxes (HXXXH, HXXHH, XXXHH), a FA_desaturases domain and three transmembrane domains suggests that SiFad1 belongs to the microsomal fatty acid desaturases family. Its tissue distribution showed that the highest expression of SiFad1 is in the intestine and the weakest expression is in Aristotle's lantern of S. intermedius. Time-course expression measurements in different developmental stages showed the highest expression of SiFad1 occurs in the gastrula and the weakest expression in the juvenile sea urchin. Knock-down of SiFad1 by specific siRNA revealed that the significantly depressed expression of Elovl5 had decreased in the coelomocytes, intestines and gonads at 24 h post transfection, indicating that the downstream target gene of SiFad1 is Elovl5 and SiFad1 and Elovl5 have positive regulatory effects. When we examined the changes in fatty acids in the gonads before and after interference, the results showed that after 24 h of interference, the content of C20:4n-6 produced by SiFad1 had decreased. Taken together, these results will enable us to understand the role of SiFad1 in fatty acid anabolism, which will help us to understand the fatty acid synthesis pathways and regulatory mechanisms of Strongylocentrotus intermedius and provide a theoretical experimental basis for improving the ability of sea urchins to synthesize fatty acids and cultivating sea urchins of higher quality and nutritional value.
脂肪酸去饱和酶（Fads）是生物合成高度不饱和脂肪酸（HUFAs）过程中的关键酶。在这项研究中，我们克隆了中间太平洋石斑鱼 SiFad1 基因（SiFad1）的全长序列，并分析了其在不同发育阶段和不同组织中的表达谱。SiFad1 的全长 cDNA 由 1086bp 组成，具有 885bp 的推定开放阅读框，编码 294 个氨基酸（AA）残基的多肽。SiFad1 的预测分子质量为 34.67kDa，理论等电点为 8.41。存在保守基序，包括三个组氨酸盒（HXXXH、HXXHH、XXXHH）、FA_desaturases 结构域和三个跨膜结构域，表明 SiFad1 属于微粒体脂肪酸去饱和酶家族。其组织分布显示，SiFad1 的表达最高的组织是肠道，最弱的组织是中间太平洋石斑鱼的 Aristotle's lantern。在不同发育阶段的时间过程表达测量中，SiFad1 的表达最高发生在原肠胚期，最弱发生在幼年海胆。特异性 siRNA 敲低 SiFad1 后，在转染后 24 小时的体腔细胞、肠道和性腺中，Elovl5 的表达显著下调，表明 SiFad1 的下游靶基因是 Elovl5，SiFad1 和 Elovl5 具有正调控作用。当我们检查干扰前后性腺中脂肪酸的变化时，结果表明干扰 24 小时后，由 SiFad1 产生的 C20:4n-6 的含量减少了。综上所述，这些结果将使我们能够了解 SiFad1 在脂肪酸生物合成中的作用，这将有助于我们了解中间太平洋石斑鱼的脂肪酸合成途径和调控机制，并为提高海胆合成脂肪酸的能力和培育更高质量和营养价值的海胆提供理论实验基础。
