Association of missense MTTP gene polymorphism with carcass characteristics and meat quality traits in pigs

Microsomal triglyceride transfer protein, coded by MTTP gene, has multiple functions including participation in formation of chylomicrons, low-density lipoproteins, and very low-density lipoproteins. Therefore MTTP protein plays a key role in the transport of fats and cholesterol between membrane vesicles, which can be associated with lipid metabolism. In the present study, ENSSSCT00000010052.2:c.2518C>T (rs335896411) missense polymorphism (Leu>Phe) located in exon 18 of MTTP gene was investigated in order to estimate its potential association with production traits of pigs. The analysis was performed with five breeds (Duroc, Landrace, Large White, Pietrain, Pulawska pigs) and totally 678 pigs, for which the genotypes of c.2518C>T polymorphism were identified by the polymerase chain reaction-restriction fragment length polymorphism method. The present study showed a significant association of c.2518C>T polymorphism with carcass yield. When analyzing the whole population, CC homozygotes showed significantly higher carcass yield than heterozygotes (P ≤ 0.05). Moreover, c.2518C>T single nucleotide polymorphism (SNP) affected pH measured in loin (m. longissimus dorsi) and ham (m. semimembranosus) 45 min after slaughter. For both parameters, the highest pH values were obtained for CC pigs, while the lowest for heterozygotes (P ≤ 0.05). The SNP analyzed was also related with meat colour (yellowness intensity (b*)). Previous research confirmed that ENSSSCP00000009789.2:p.Leu840Phe polymorphism, via affecting MTTP protein activity, influences metabolism of fatty acids. Additionally, results obtained in the present study suggest that the analyzed missense mutation in porcine MTTP gene can be one of the potential genetic factors associated with meat quality (pork pH and colour) and carcass yield.