Minnesota Science
Vol. 49, No. 1
PSS Is Early Target Of Biotech Disease Hunters
by Larry Etkin
Porcine Stress Syndrome is one genetic problem with pig production that biotechnology is on the path toward eliminating. Caused by a recessive gene that must be inherited from both parents, PSS has proved very resistant to elimination from breeding herds. It is a muscular disorder that causes some afflicted animals to die from stresses, such as are caused when they are being transported, or to deteriorate and bring lower prices at market.
The new techniques identified a genetic marker associated with where the mutation appears on a gene. Restriction enzymes sliced up gene strands at specific places where recognized patterns occurred, and a technique called polymerase chain reactions multiplied the DNA fragments to make analysis easier. Electrophoresis sorted the gene fragments into visual patterns that could be compared to locate appropriate markers for the section of the genes of economic interest.
Pre-genetic tests for PSS could only identify animals with the actual syndrome, not one harboring the mutation on a single gene. Now, the FABCenter has a blood test that can find single gene carriers, and has tested thousands of blood samples from around the country for the National Pork Producers Association.
"Economic pressures on breeding stock suppliers to have their animals tested is growing," says Jim Mickelson, one of the test's developers. Some producers, like Minnesota based Dean Compart, have tested their entire herds and completely eliminated PSS carriers. "The benefits," he says, "far outweigh the cost of the tests."