[Objective] The aim of this study is to clone bovine interleukin-2 gene(IL-2)and observe its expression in prokaryotic cells.[Method]Bovine IL-2 gene was amplified from total RNA of peripheral blood lymphocytes of hol...[Objective] The aim of this study is to clone bovine interleukin-2 gene(IL-2)and observe its expression in prokaryotic cells.[Method]Bovine IL-2 gene was amplified from total RNA of peripheral blood lymphocytes of holstein-friesian cows by RT-PCR.Subsequently,the gene was cloned into pGEX-2T prokaryotic expression plasmid to construct recombinant,which was then transformed into Escherichia Coli BL21.After IPTG induction,SDS-PAGE analysis was conducted.[Result]A 500 bp target fragment corresponding with expectation was obtained by RT-PCR.The cloned gene successfully expressed fusion protein of about 43 kD in prokaryotic cells.[Conclusion]This study provided a theoretical and material basis for further researches on IL-2 gene.展开更多
Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the productio...Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or high in rumen undegraded protein.展开更多
There are three main cattle breeds in Mauritius;the Friesian cows, the Creole cows and the Cross (Creole and Friesians) breeds. The main objective of the study was to differentiate the Creole breeds from the other two...There are three main cattle breeds in Mauritius;the Friesian cows, the Creole cows and the Cross (Creole and Friesians) breeds. The main objective of the study was to differentiate the Creole breeds from the other two breeds thus valorizing and conserving the Creole cow which is in danger of extinction. Random Amplified Polymorphic DNA and random microsatellite analysis were the two PCR based techniques used. The populations studied consisted of 5 Friesians, 5 Creole breeds and 5 Cross breeds. The breeds were obtained from the Curepipe Livestock Research Station which is the only place where there is a record of Creole cows in Mauritius. Among the 5 Creoles breeds chosen, 2 of them could have been impure breeds due to their morphological characteristics. DNA extraction was carried out from blood taken from the cows selected, and yielded DNA of good quality and quantity. Polymorphic bands were obtained from the Random Amplified Polymorphic DNA primers and random microsatellite primers and the data obtained were used for constructing a dendogram. From the dendogram obtained, the breeds were separated and the two Creole samples, which were suspected to be impure, formed different clusters from the true Creole breeds. From the results obtained, the Creole breed was easily distinguishable from the other breeds studied using molecular techniques.展开更多
文摘[Objective] The aim of this study is to clone bovine interleukin-2 gene(IL-2)and observe its expression in prokaryotic cells.[Method]Bovine IL-2 gene was amplified from total RNA of peripheral blood lymphocytes of holstein-friesian cows by RT-PCR.Subsequently,the gene was cloned into pGEX-2T prokaryotic expression plasmid to construct recombinant,which was then transformed into Escherichia Coli BL21.After IPTG induction,SDS-PAGE analysis was conducted.[Result]A 500 bp target fragment corresponding with expectation was obtained by RT-PCR.The cloned gene successfully expressed fusion protein of about 43 kD in prokaryotic cells.[Conclusion]This study provided a theoretical and material basis for further researches on IL-2 gene.
文摘Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or high in rumen undegraded protein.
文摘There are three main cattle breeds in Mauritius;the Friesian cows, the Creole cows and the Cross (Creole and Friesians) breeds. The main objective of the study was to differentiate the Creole breeds from the other two breeds thus valorizing and conserving the Creole cow which is in danger of extinction. Random Amplified Polymorphic DNA and random microsatellite analysis were the two PCR based techniques used. The populations studied consisted of 5 Friesians, 5 Creole breeds and 5 Cross breeds. The breeds were obtained from the Curepipe Livestock Research Station which is the only place where there is a record of Creole cows in Mauritius. Among the 5 Creoles breeds chosen, 2 of them could have been impure breeds due to their morphological characteristics. DNA extraction was carried out from blood taken from the cows selected, and yielded DNA of good quality and quantity. Polymorphic bands were obtained from the Random Amplified Polymorphic DNA primers and random microsatellite primers and the data obtained were used for constructing a dendogram. From the dendogram obtained, the breeds were separated and the two Creole samples, which were suspected to be impure, formed different clusters from the true Creole breeds. From the results obtained, the Creole breed was easily distinguishable from the other breeds studied using molecular techniques.
