Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
May 02, 2001
Transgenic animals are environmentally friendly, study says
It is possible to genetically alter animals to produce manure with less environmentally damaging phosphorus, new research by University of Guelph professors reveals.
The findings of molecular biologist John Phillips, microbiologist Cecil Forsberg and graduate student Serguei Golovan were published in this week’s issue of Nature Biotechnology. The study examined mice that were genetically modified so their bodies would absorb more phosphorus from their diet. The result was an 11- per- cent reduction in the fecal phosphorus of the transgenic rodents.
“The fact that phosphorus levels were reduced in the mouse models shows that the gene is working,” Phillips said, referring to a composite gene that Golovan created to make the transgenic mice. The researchers took an E. coli gene that makes the enzyme phytase and a mouse gene that controls the production of a protein secreted in the salivary glands and made a new gene. That composite gene was inserted into the nucleus of a one-celled mouse with a microscopic needle. The gene allows the mouse to make phytase in the salivary gland and secrete it into its saliva, where it is swallowed with food. The phytase releases organic phosphorus in the rodent’s gut that can be absorbed by the bloodstream.
“This research shows that this is a promising biological approach to reducing the phosphorus content of manure,” Phillips said. In fact, he added, phosphorus reductions may even be greater in farm animals because mice recycle phosphate, which may make the decrease of phosphorus levels in their manure appear less substantial.
Animal waste is a leading source of phosphorus pollution from agriculture. Phosphorus pollutes surface and groundwater and promotes the growth of algae in rivers, lakes and streams, reducing available oxygen to fish and aquatic life. “Our results with these transgenic mouse models suggest that producing farm animals with the same gene is a plausible way to create more sustainable animal agriculture,” Forsberg said.
Two years ago, Phillips, Forsberg and Golovan announced they had produced transgenic pigs that carry the same composite gene. They have been conducting research trials on the animals and are expected to publish results in the next few months. “This research is a prelude to what we hope to find with the transgenic pigs,” said Phillips. “It also sets the framework for future work involving other transgenic farm animals.”
Prof. John Phillips, Department of Molecular Biology
Prof. Cecil Forsberg, Department of Microbiology
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