Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease a...Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene （sFat-1） from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6：ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.展开更多
Delta-12 oleate desaturase gene （FAD2-1） which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cott...Delta-12 oleate desaturase gene （FAD2-1） which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed.展开更多
Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based o...Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based on the assumption that the glucose-insulin axis is central for the metabolic activities,which led to type 2 diabetes.However,significant downregulation of both the NKX2-1 gene and the TPD52L3 gene force an increase in the release of free fatty acids(FFAs)into the blood circulation,which leads to a marked reduction in membrane flexibility.These data favor a FFA-glucose-insulin axis.The authors are invited to extend their study with the introduction of the saturation index(number of carbon-carbon double bonds per 100 fatty-acyl chains),as observed in erythrocytes.展开更多
由于耐药性的产生和化疗药物的毒副反应,恶性肿瘤的化疗效果一直不满意。为了寻找新的、选择性的抗肿瘤药物,人们对肿瘤细胞的代谢异常作了大量研究。越来越多的研究发现,肿瘤组织的恶性生物学行为与其特殊的物质代谢和能量代谢密切相...由于耐药性的产生和化疗药物的毒副反应,恶性肿瘤的化疗效果一直不满意。为了寻找新的、选择性的抗肿瘤药物,人们对肿瘤细胞的代谢异常作了大量研究。越来越多的研究发现,肿瘤组织的恶性生物学行为与其特殊的物质代谢和能量代谢密切相关。增殖迅速的肿瘤细胞的一个代谢特点为脂质生成增多。硬脂酰辅酶A去饱和酶1(Stearoyl-coenzyme A desatu-rase 1,SCD1)是催化饱和脂肪酸向单不饱和脂肪酸转变的限速酶,与肥胖、脂肪性肝脏病变、胰岛素抵抗等一系列的代谢综合征及癌症的发生、发展密切相关。研究SCD1在恶性肿瘤中的作用将为肿瘤患者化疗提供新的治疗靶点。展开更多
基金supported by the National Transgenic Breeding Project, China (2008ZX08010-004)the National Natural Science Foundation of China (30830080)+1 种基金the National Basic Research Program of China (G2006CB102105, 2009CB941604)the National High Technology Research and Development Program of China (20060110Z1039, 2008AA10Z143)
文摘Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene （sFat-1） from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6：ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.
文摘Delta-12 oleate desaturase gene （FAD2-1） which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed.
文摘Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based on the assumption that the glucose-insulin axis is central for the metabolic activities,which led to type 2 diabetes.However,significant downregulation of both the NKX2-1 gene and the TPD52L3 gene force an increase in the release of free fatty acids(FFAs)into the blood circulation,which leads to a marked reduction in membrane flexibility.These data favor a FFA-glucose-insulin axis.The authors are invited to extend their study with the introduction of the saturation index(number of carbon-carbon double bonds per 100 fatty-acyl chains),as observed in erythrocytes.
文摘由于耐药性的产生和化疗药物的毒副反应,恶性肿瘤的化疗效果一直不满意。为了寻找新的、选择性的抗肿瘤药物,人们对肿瘤细胞的代谢异常作了大量研究。越来越多的研究发现,肿瘤组织的恶性生物学行为与其特殊的物质代谢和能量代谢密切相关。增殖迅速的肿瘤细胞的一个代谢特点为脂质生成增多。硬脂酰辅酶A去饱和酶1(Stearoyl-coenzyme A desatu-rase 1,SCD1)是催化饱和脂肪酸向单不饱和脂肪酸转变的限速酶,与肥胖、脂肪性肝脏病变、胰岛素抵抗等一系列的代谢综合征及癌症的发生、发展密切相关。研究SCD1在恶性肿瘤中的作用将为肿瘤患者化疗提供新的治疗靶点。
