Authors : Jinfeng Miao, Qiaoxiu Wang, Jian Lin, Qiang Zhang and Qian Yang
Abstract: The aim of this study was to determine if intramammary infusion of recombinant expression vectors and subsequent analyses of whey proteins can be used to evaluate plasmid function and to elucidate their mechanisms of improving milk production. On the day of the experiment, 6 goats were infused with 100 μg g-1 and of recombinant vectors pcGH-20 or pIN in both right and left glands. At intervals of 0 (control group), 1, 3 and 7 days Post Infusion (PI), milk was collected. Whey from each time point was compared to controls by 2-Dimensional gel Electrophoresis (2-DE) with colloidal coomassie staining and matrix-assisted desorption/ionization mass spectrometry. In the pIN infusion group, 19 protein spots with a 2 fold or greater change from the controls were obtained. In the pcGH-20 infusion group 14 protein spots were produced. The proteins were sorted into 5 functional classes based on Conserved Domain Database (CDD) comparison. Some spots corresponded to the major milk proteins. Some are involved in host defense/immune functioning, others in metabolism and still others are hormone and hormone-like factor. The remaining proteins serve other functions. The upregulation of some important metabolism related proteins (including hormone and hormone-like factors) indicates that mammary epithelial cells respond to recombinant vector infusion. The data also show that different plasmids induce different whey profiles. Further, development of this model could be used to evaluate the function of recombinant vectors and to elucidate their potential mechanism of action prior to the production of transgenic animals.
Jinfeng Miao, Qiaoxiu Wang, Jian Lin, Qiang Zhang and Qian Yang, 2013. Differential Protein Composition of Goat Whey Before and After Intramammary Plasmid Infusion. Journal of Animal and Veterinary Advances, 12: 1454-1460.