| Transgenic mice were produced with a construct, designed to allow pancreatic acini specific expression of a human growth hormone signal peptide/CelD fusion, pGUT 22. Cellulolytic activity was not detectable in the transgenic mice. To facilitate this and future work, a series of plasmids was constructed with and without an intron, with and without a signal peptide, and all with the strong viral promoter from Rous Sarcoma Virus (RSV). One of these plasmids, pEPcelD, allows expression of cloned coding regions in both mammalian and prokaryotic cells with selectable markers, promoter regions, translational starts and origins of replications for both cell-types. Plasmids containing the pancreatic acini specific promoter from the rat elastase I gene (rEI) were also constructed with identical cloning sites to the RSV plasmids to allow easy cloning of tissue culture tested coding regions into a pancreas specific context. One of the rEI plasmids, pGUT II, also allows functional confirmation of the cloned coding region in E. coli. A functional cellulase was not expressed in mammalian cells from the celD coding region in plasmids with (pREP 22 and pREP... |
