In this experiment, 500 bp cDNA of myostatin gene was cloned from a Beijing duck＇s breast, The duck myostatin gene was found to have 98, 96, 95, 88, and 87% sequence similarity at the cDNA level with domestic goose, ...In this experiment, 500 bp cDNA of myostatin gene was cloned from a Beijing duck＇s breast, The duck myostatin gene was found to have 98, 96, 95, 88, and 87% sequence similarity at the cDNA level with domestic goose, chicken, domestic pigeon, human, and pig, respectively. The predicted amino acid sequence has an overall similarity with a comparable region of turkey 99%, domestic goose 98%, and chicken 99%. Conserved domains of deduced amino acids showed that it belonged to the TGF-beta family. Myostatin expression in breast muscle was higher at 28, 35, and 42 days than at 7, 14, and 21 days. The pattern of myostatin expression was closely parallel to the trend of breast muscle growth, suggesting that myostatin might play an important role in breast muscle development. It was possible to postulate that myostatin may be a major determinant of muscle mass in breast muscle, as shown in other species.展开更多
It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly car...It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly carried by HDL and metabolized through an HDL receptor pathway in the liver. However, evidence of this receptor′s existence in the liver is not yet complete. In this paper. the HDL receptor in BD liver has been studied. Our experiments showed : 1 ) ApoE-free 125 I-HDL could bind specifically to duck hepatic cell membrane with high affinity (Kd=9.6μg/ml) and was saturable (Bmax=8.9μg/mg cell membrane protein)at room temperature 2)Competitive inhibition studies with unlabelled duck, human, rat and chick HDL and duck apo AI and its liposomes formed with PC or DMPC could inhibit the binding of 125I-HDL to duck hepatic cell membranes, but LDL,apo E and their liposomes with PC or DMPC could not with the exception of duck LDL. 3) The receptor could recognize apo AI but not apo B or E. 4 ) Both phosphorase A2 and pronase could inhibit the binding activity. The above results give strong evidence for the existence of a specific HDL receptor pathway in the duck liver, supporting our hypothesis that CE in Beijing ducks is metabolized directly through the hepatic HDL receptor instead of being transfered back to VLDL and LDL, then through the LDL receptor pathway. This unique way of metabolizing CE may be behind the Beijing duck's antiatherogenicity.展开更多
基金The experiment was sponsored by Academic Science Foundation of the Chinese Academy of Agricultural Sciences(2006)the Special Research Program of China(waterfowl healthy feeding technology).
文摘In this experiment, 500 bp cDNA of myostatin gene was cloned from a Beijing duck＇s breast, The duck myostatin gene was found to have 98, 96, 95, 88, and 87% sequence similarity at the cDNA level with domestic goose, chicken, domestic pigeon, human, and pig, respectively. The predicted amino acid sequence has an overall similarity with a comparable region of turkey 99%, domestic goose 98%, and chicken 99%. Conserved domains of deduced amino acids showed that it belonged to the TGF-beta family. Myostatin expression in breast muscle was higher at 28, 35, and 42 days than at 7, 14, and 21 days. The pattern of myostatin expression was closely parallel to the trend of breast muscle growth, suggesting that myostatin might play an important role in breast muscle development. It was possible to postulate that myostatin may be a major determinant of muscle mass in breast muscle, as shown in other species.
文摘It had been found that Beijing ducks(BD) have a high level of HDL(70%), high LCAT but very low CETP activity and will not develop atherosclerosis on an atherogenic diet, suggesting that cholesterol ester is mainly carried by HDL and metabolized through an HDL receptor pathway in the liver. However, evidence of this receptor′s existence in the liver is not yet complete. In this paper. the HDL receptor in BD liver has been studied. Our experiments showed : 1 ) ApoE-free 125 I-HDL could bind specifically to duck hepatic cell membrane with high affinity (Kd=9.6μg/ml) and was saturable (Bmax=8.9μg/mg cell membrane protein)at room temperature 2)Competitive inhibition studies with unlabelled duck, human, rat and chick HDL and duck apo AI and its liposomes formed with PC or DMPC could inhibit the binding of 125I-HDL to duck hepatic cell membranes, but LDL,apo E and their liposomes with PC or DMPC could not with the exception of duck LDL. 3) The receptor could recognize apo AI but not apo B or E. 4 ) Both phosphorase A2 and pronase could inhibit the binding activity. The above results give strong evidence for the existence of a specific HDL receptor pathway in the duck liver, supporting our hypothesis that CE in Beijing ducks is metabolized directly through the hepatic HDL receptor instead of being transfered back to VLDL and LDL, then through the LDL receptor pathway. This unique way of metabolizing CE may be behind the Beijing duck's antiatherogenicity.
