Transgenic mice expressing bacterial phytase as a model for phosphorus pollution control

• Published in: Nature biotechnology Vol. 19; no. 5; pp. 429 - 433
• Main Authors: Phillips, John P, Forsberg, Cecil W, Golovan, Serguei P, Hayes, M. Anthony
• Format: Journal Article
• Language: English
• Published: New York, NY Nature 01.05.2001; Nature Publishing Group
• Subjects: 6-Phytase - genetics; Acid Phosphatase - genetics; Animals; appA gene; Bioavailability; Biological and medical sciences; Biotechnology; Blotting, Northern; E coli; Electrophoresis, Polyacrylamide Gel; Environmental impact; Environmental Pollution - prevention & control; Escherichia coli; Escherichia coli Proteins; Exocrine glands; Feces - chemistry; Feeds; Female; Females; Fundamental and applied biological sciences. Psychology; Genetic engineering; Genetic technics; Immunohistochemistry; Male; Manure - analysis; Manures; Methods. Procedures. Technologies; Mice; Mice, Transgenic - physiology; Parotid Gland - enzymology; Phosphates; Phosphorus; Phosphorus - metabolism; Pollution; Poultry; Proteins; Publishing; Rats; Submandibular Gland - enzymology; Transgenic animals; Transgenic animals and transgenic plants; Animal model; Enzyme; Escherichia coli; Rodentia; 6-Phytase; Phosphoric monoester hydrolases; Transgenic animal; Tissue specificity; Salivary gland; Phosphorus; Esterases; Bioavailability; Gene expression; Phytic acid; Vertebrata; Pollution; Mammalia; Mouse; Bacteria; Hydrolases; Feces; Enterobacteriaceae
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/88091

We have developed transgenic mouse models to determine whether endogenous expression of phytase transgenes in the digestive tract of monogastric animals can increase the bioavailability of dietary phytate, a major but indigestible form of dietary phosphorus. We constructed phytase transgenes composed of the appA phytase gene from Escherichia coli regulated for expression in salivary glands by the rat R15 proline-rich protein promoter or by the mouse parotid secretory protein promoter. Transgenic phytase is highly expressed in the parotid salivary glands and secreted in saliva as an enzymatically active 55 kDa glycosylated protein. Expression of salivary phytase reduces fecal phosphorus by 11%. These results suggest that the introduction of salivary phytase transgenes into monogastric farm animals offers a promising biological approach to relieving the requirement for dietary phosphate supplements and to reducing phosphorus pollution from animal agriculture.