[Gene transfer in swine by DNA microinjection into zygotes]

The techniques for the production of transgenic pigs are described. Once a gene interesting for animal breeding is found, a gene construct is cloned. The gene construct is a combination of a structure gene and a promoter region which regulates the gene expression of the transgene. The DNA solution is microinjected into the pronuclei of fertilized ova. The injected ova are transferred to synchronised recipient pigs. The animals born must be controlled for the integration of the injected gene construct. In transgenic offspring the expression of the gene, the heredity to the next generation and the biological activity have to be tested. The overall efficiency of a gene transfer programme in pig is about 0.5%. This is lower than in similar projects in mice.