A research group led by Iowa State University (ISU) has expanded mapping of the pig genome, which will aid swine genetic research.

The group created a library of 21,499 pig gene sequences and mapped the location of 727 of those genes on pig chromosomes.

The results will help researchers access the sequences or chunks of DNA to further identify and map pig genes. DNA are chemicals that carry the code of living matter.

The 727 genes the research teams mapped are mainly associated with reproduction: the pituitary gland, placenta, uterus, embryo, hypothalamus and ovary. That represents about a third of the 2,000 pig genes that have been mapped worldwide, says Christopher Tuggle, ISU animal science professor and project leader.

Project cooperators included the University of Iowa, University of Missouri, University of Nebraska and the National Center for Genomic Resources.

The three-year, $700,000 project was funded by the U.S. Department of Agriculture.

Funding also produced probes to detect the expression of specific genes in pigs. Breeders can use the probes to determine if a gene is expressed or active in a pig and then breed animals with desirable gene expression, says Tuggle.

Scientists could also use the sequence information to manipulate pig genes. At the University of Missouri, Randy Prather is developing small pigs whose organs may be transplanted into humans. "He can modify and make a specific change (to the pig genome), and to do that he can use the information the project has provided," says Tuggle.

Biomedical researchers see pigs as a model for human disease, he adds. University of Iowa researchers want to study gene expression in placental tissues to learn how placental cancers occur in humans.

Software tools were developed by the researchers to enable them to compare the pig gene sequences identified with databases of human and pig genes. This process can help map the genes and determine their functions.