| 摘要: |
| 利用 RT-PCR 和 RACE 方法克隆得到鳜鱼肝脏中控制高不饱和脂肪酸合成的脂肪酸去饱和酶(fatty acid desaturase, FAD)和脂肪酸延长酶(fatty acid elongase, ELO)基因的全长 cDNA 序列。FAD基因的全长 cDNA 序列 1882bp, 编码 445 个氨基酸, 该蛋白序列含有 FAD 全部的特征结构区, 包括3 个组氨酸簇、2 个跨膜区和1 个细胞色素 b5结构域, 与其它鱼类FAD氨基酸序列的同源性为 66.5%—90.1%, 系统树分析显示其与欧洲鲈鱼和金头鲷等海水鱼类的亲缘关系最近。获得的 ELO 基因全长 cDNA 序列 1401bp, 编码 294 个氨基酸, 该蛋白序列含有单一的氧化还原中心组氨酸簇、内质网停留信号和多个跨膜区等ELO特征结构, 与其它几种鱼类ELO氨基酸序列的同源性为71.8%—86.7%, 系统进化分析显示其与南方蓝鳍金枪鱼和金头鲷的亲缘关系较近。 鳜鱼 FAD 和 ELO 基因全长 cDNA序列的获得可为进一步研究其 HUFA 合成能力及调控机理奠定基础。
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| 关键词: 脂肪酸去饱和酶, 脂肪酸延长酶, 基因克隆, 序列分析, 鳜鱼 |
| DOI：10.11693/hyhz201006011011 |
| 分类号: |
| 基金项目:国家高技术研究与发展计划(863 计划)项目, 2007AA09Z437 号; 国家自然科学基金项目, 30670367 号; 广东省科技计划项目, 2005B20301005 号; 广东省自然科学基金项目, 031886 号 |
附件 |
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| CLONING AND ANALYSIS OF THE FATTY ACID DESATURASE AND ELONGASE GENES OF MANDARIN FISH SINIPERCA CHUATSI |
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LI Guan-Gui, LIANG Xu-Fang, YU Ying, LAI KAA-SENG, LI Jin-Guang
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College of Life Science and Technology, Jinan University
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| Abstract: |
| The full-length cDNAs of fatty acid desaturase (FAD) and fatty acid elongase (ELO), the two enzymes that closely involved in biosynthesis of highly unsaturated fatty acids (HUFA), were isolated from mandarin fish Siniperca chuatsi by RT-PCR and RACE methods. The FAD cDNA was 1882bp in length, including an ORF of 1338bp specifying a protein of 445 amino acids. The protein sequence contained all the characteristics of microsomal fatty acid desaturases, including three histidine boxes, two transmembrane regions, and a cytochrome b5 domain. The deduced amino acid sequence shared 66.5%—90.1% identity with other fishes, and the phylogenetic tree shows that it clustered closely with European seabass and gilthead seabream, two marine species. The 1401bp cDNA of ELO included 885bp ORF, encoding a 445 amino acid peptide containing a single histidine box redox center motif; a canonical ER retention signal and multiple transmembrane regions are similar to other fatty acid desaturases. The protein sequence had 71.8%—86.7% identity with
other fish species. In phylogenetic tree, it clusters closely with southern bluefin tuna and gilthead seabream. The results would promote future study on the HUFA biosynthesis pathway of mandarin fish.
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| Key words: Fatty acid desaturase, Fatty acid elongase, Gene cloning, Sequence analysis, Mandarin fish Siniperca chuatsi |
