SR9098 - Production of Transgenic Pigs that are More Resistant to Disease

Researcher:

Dr. Julang Li, Dept. of Animal & Poultry Science, University of Guelph

Objectives:

1. To develop transgenic pigs with controlled expression of protegrin 1 in the epithelial of the digestive tract and airways by gene targeting and nuclear transfer and thus eliminate the use of antibiotics in the pig industry.

Expected Benefits:

The transgenic pigs will be beneficial to the Ontario pork industry in the following three aspects:

1. reduce cost of medical treatment

2. resistance to disease because of their stronger innate immune system

3. the transgenic pigs wll be treated with far less or no antibiotics which means that the pork industry will be in a much better position to retain global consumer confidence in a safe Canadian food supply.

Summary of Research Results:

This is a report on the progress of the first phase (three years) of a six year project. In summary, we have isolated a tracheal epithelial specific inducible promoter from bovine genome and demonstrated that it has similar activity in porcine tracheal epithelial cells. This tracheal antimicrobial peptide (TAP) promoter will be utilized to drive Protegrin expression in our construct for transgenic pig production. We have isolate three antimicrobial peptides: Protegrin 1, cecropin, and TAP and cloned them into expression vector to test their activity in epithelial cells in vitro, and to identify sequence components that are critical for their high level expression and secretion. Experiments of this section are still on going. In term of the establishment of the gene targeting system in porcine cells, we have cloned and sequenced the 14.7 kb porcine HPRT fragment and are in the stage of the making construct for gene targeting.

We have established the pig nuclear transfer and embryo culture system in the Department of Animal and Poultry Science. We are now collaborating with nuclear transfer experts from South Korea in an attempt to improve the pregnancy rate after embryo transfer, and hope to obtain cloned piglets in the near future.