Strategies for Diagnosis of Diseases in Pigs Using Molecular Markers Review.

In certain breeds of pigs were identified the porcine stress syndrome (PSS) that determine the appearance of some carcasses inadequate for processing. Because PSS can be triggered by halothane, the gene responsible for the syndrome is often referred to as the "halothane gene" (Hal). The metabolic and physiological changes that occur in halothane positive pigs (homozygous recessive "nn") are produced by gene located in the Hal locus responsible for synthesis of the Ca2 + channel receptor in the sarcoplasmatic reticulum of skeletal muscle fiber, called Ryanodin receptor (RYR1). The Ryanodin receptor locus in pig populations is important not only for economic losses caused by homozygous recessive pigs, but also for the fact that this locus is linked to other quantitatively additive genes which determine muscle hypertrophy. The unconscious promotion of carrier and positive animals in the herd, due to the intention to produce a new generation characterized by muscle hypertrophy, led to the automatic increase of frequency of the mutant allele "n" in the pig population. PCR assay of porcine genetic background can help determine with great precision the frequency of specific alleles in the RYR1 locus, offering the specialists a possibility of reducing the recessive allele frequency through selection. Therefore, the present review underlines the necessity of implementing such testing programs in Romania in order to prevent the risk of dissemination of PSS in pigs. [ABSTRACT FROM AUTHOR]