胡麻脂肪酸脱氢酶基因fad3b过表达小鼠模型的建立及其功能分析

The Role of Fatty Acid Desaturase in Flax fad3b in Transgenic Mice Model

脂肪酸脱氢酶3(fatty acid desaturase 3,fad3)是高等植物细胞中一种催化n-6多不饱和脂肪酸转化为n-3多不饱和脂肪酸的酶。该研究将胡麻fad3b基因转染小鼠C2C12细胞,转基因细胞中的n-6多不饱和脂肪酸含量显著降低,n-3多不饱和脂肪酸含量显著升高。Fad3b转基因小鼠中,fad3b基因在不同组织器官的m RNA水平与蛋白质水平的表达趋势并不一致。在fad3b m RNA水平上,肝脏中最高,骨骼肌、脂肪、脑和心脏中较低;在脂肪酸水平上,骨骼肌、脑和肝脏等组织的n-6/n-3显著降低,而脂肪、卵巢和睾丸组织中的变化不显著。该研究结果提示,胡麻来源的fad3b基因能够在转基因小鼠中正常发挥功能,促使n-6向n-3多不饱和脂肪酸转化,fad3b转基因小鼠模型可能比fat1小鼠在基因功能专一性以及动物生殖健康等方面更有优势。

The fatty acid desaturase 3（fad3） played a pivotal role in convert n-6 polyunsaturated fatty acids（n-6 PUFAs） to n-3 PUFAs in plants. In this study, fad3b, a family member of fad3 from Linum usitatissimum Linn was tranfected into C2C12 myoblasts. The n-6 PUFAs were significant decrease, and the n-3 PUFAs were significant increase in the transfected cells. Fad3 b transgenic mice were produced by pronuclear microinjection, and the relative expression of fad3b in tissue were analysized. The results showed that in compared to non-transgenic mice, highest m RNAs level of fad3b was detected in liver, and its lower levels in skeletal muscle, fat, brain and heart. In addition, there is a significant reduction of n-6/n-3 PUFAs ratios in skeletal muscle, brain and liver, but no difference in fat, ovary and testis between transgenic and non-transgenic mice. Altogether, fatty acid desaturase fad3b from Linum usitatissimum Linn could be expressed in mouse myoblasts and transgenic offspring, and play the role to convert n-6 PUFAs to n-3 PUFAs in mammalian tissues. These results confirmed that in compared to fat1, the function of fad3b was more concentrated, and fad3b transgenic mouse could be more appropriate model for fertility studies.