摘要
旨在揭示变温鱼类合成HUFAs过程中的关键酶及其功能,以锦鲤(Cyprinus carpiokoi)为材料,通过RT-PCR扩增获得了一段长度为854 bp的Δ6脂肪酸去饱和酶基因的c DNA序列片段,并对其进行了序列分析和蛋白产物结构预测。结果显示,该片段与南亚野鲮(Labeo rohita)Δ6脂肪酸去饱和酶基因有93.5%的同源性,编码的蛋白产物具有典型的Δ6脂肪酸去饱和酶结构特点,包含2个组氨酸保守区(HDFGH、HFQHH)和2个跨膜结构域。荧光定量PCR表明,Δ6脂肪酸去饱和酶在锦鲤肝脏中的表达量最高,在肠、脑和心脏中表达量依次降低,而在肌肉和鳃的表达量相对较低。幼鱼在不同培养水温下,各组织中该基因的表达量均随温度的下降而升高,以适应低温环境。
Highly unsaturated fatty acids（HUFAs）are important constituents of cell membrane, and the unsaturated degree of carbon chain is an important factor in resisting to low temperature, maintaining and regulating the fluidity of cell membrane. In order to discover the key enzymes of synthetizing HUAs and their functions, using koi carp（Cyprinus carpiokoi）as studying materials, a 854 bp c DNA of delta 6 fatty acid desaturase（Fad6）was amplified by RT-PCR, their sequences were analyzed and the structures of proteins were predicted. Results showed that the amplified fragment had great homology（93.5%）with that of rohu（Labeo rohita）. The encoded protein possessed the features of typical Fad6, containing two histidine boxes（HDFGH and HFQHH）and two transmembrane regions. Real time PCR results demonstrated that Fad6 was expressed in all tissues, and the order of their expression levels was as follows ：liver intestine brain heart muscle gill. The expressions of the Fad6 gene in different tissues of koi carp larva, while exposing to different water temperatures, increased as water temperature decreasing for adapting to the lower temperature environment.
出处
《生物技术通报》
CAS
CSCD
北大核心
2015年第12期158-166,共9页
Biotechnology Bulletin
基金
国家自然科学基金项目(31171198)
关键词
锦鲤
高不饱和脂肪酸
△6脂肪酸去饱和酶
鱼类抗冻
koi carp
highly unsaturated fatty acids
delta 6 fatty acid desaturase
fish antifreeze
