论文部分内容阅读
利用逆转录PCR和RACE技术获得建鲤2种Δ6脂肪酸去饱和酶(FADs6-a,FADs6-b)的全长cDNA序列.FADs6-a基因的cDNA总长为1 966 bp,开放阅读框为1 335 bp,编码444个氨基酸;FADs6-b基因的cDNA总长为1 931 bp,开放阅读框为1 335 bp,编码444个氨基酸.FADs6-a和FADs6-b基因都包括N端细胞色素b5结构域、3个富含组氨酸的结构域和2个推测的跨膜区,具有典型的Δ6脂肪酸去饱和酶结构特点.氨基酸同源性分析显示,建鲤FADs6-a和FADs6-b与斑马鱼的相似性较高,而与海水鱼类的相似性较低,与人类FADs6的相似性高于与FADs5的相似性.通过实时荧光定量PCR(RT-qPCR)检测该基因在建鲤幼鱼不同组织中的表达量,发现2种Δ6脂肪酸去饱和酶基因在建鲤肝脏的表达量最高,其次是肠、脑、肌肉、心和肾,而前肠高于后肠,FADs6-a的表达量高于FADs6-b.得到的结论是,建鲤具有2种类型的合成高度不饱和脂肪酸(HUFA)的关键酶—Δ6脂肪酸去饱和酶,在肝脏和肠道中的含量较多,且FADs6-a和FADs6-b在结构和组织的表达方面都存在差异,这为进一步研究建鲤HUFA的合成途径及调控机理奠定了基础.
The full-length cDNA sequences of two Δ6 fatty acid desaturases (FADs6-a, FADs6-b) from Jian carp were obtained by RT-PCR and RACE techniques.The total length of cDNA of FADs6-a gene was 1 966 bp and the open reading frame was 1 335 bp encoding 444 amino acids.The FADs6-a and bFAD6-b cDNAs contained a total length of 1 931 bp and an open reading frame of 1 335 bp, encoding 444 amino acids.The FADs6-a and FADs6-b genes all included the N-terminal cytochrome b5 domain, Three histidine-rich domains and two putative transmembrane regions have typical structural features of Δ6 fatty acid desaturase.Amino acid homology analysis showed that the carp FADs6-a and FADs6-b were closely related to zebrafish Similar to that of FADs6, but similar to that of FADs6.The similarity of FADs6 to human FADs6 was higher than that of FADs5.The results of real-time fluorescent quantitative PCR (RT-qPCR) The results showed that the expression of two Δ6 fatty acid desaturase genes in the liver of Jian carp was the highest, followed by the intestine, brain, muscle, heart and kidney, while the expression of FADs6-a was higher in the foregut than in the hindgut At FADs6-b., It was concluded that Jian carp has two types of enzymes, the key enzyme for the synthesis of highly unsaturated fatty acids (HUFA), the -6 fatty acids Desaturase, more content in the liver and intestine, and FADs6-a and FADs6-b there are differences in terms of structure and organization of expression, which laid the foundation for the biosynthesis and regulation mechanism further study of Jian carp HUFA.