Here, we report genotyping conditions for 434 new polymorphic pig microsatellite markers containing trinucleotide and tetranucleotide repeat motifs in pig. Microsatellite sequences were detected in silico from bacterial artificial chromosome (BAC) clone end sequences and mapped to the pig genome. A set of 22 microsatellites is described, which can be separated in a simultaneous electrophoresis by multiplexing across a large size range, in combination with 4-colour labelling. Marker information content and false pedigree exclusion probabilities are documented in five purebred populations, allowing assessment of this panel in pig parentage testing applications. Combined exclusion probabilities >99.7% were achieved in all pedigree test cases.

A 1000-pig F2 intercross QTL detection experimental population was generated using two commercial sire lines. Independent carriers of HAL n and RN− mutations (10% and 14%, respectively) were included in this population as control genotypes. The effects of HAL n and RN− heterozygous genotypes on fresh and transformed loins and hams were estimated using a mixed model methodology. The results document the unfavorable effects of both mutations on meat quality. Smaller effects of HAL Nn genotype compared to HAL nn or RN−rn+ genotypes were estimated. Interestingly, effects of HAL Nn genotype on meat pH and loin color could be insignificant at 24-h postmortem, but translate into higher water losses on storage and cooking, and result in tougher cooked loin. Using the same methodology, significant effects of the PRKAG3 (RN) I199 allele on ultimate pH values but not on glycolytic potential were observed.

Muscle tenderness is an important complex trait for meat quality and thus for genetic improvement through animal breeding. However, the physiological or genetic control of tenderness development in muscle is still poorly understood. In this work, using transcriptome analysis, we found a relationship between gene expression variability and tenderness. Muscle (longissimus dorsi) samples from 30 F(2) pigs were characterized by Warner-Bratzler Shear Force (WBSF) on cooked meat as a measurement of muscle tenderness. Gene expression levels were measured using microarrays for 17 muscle samples selected to represent a range of WBSF values. Using a linear regression model, we determined that samples with WBSF values above 30 N could be effectively analysed for genes exhibiting a significant association of their expression level on shear force (false discovery rate <0.05). These genes were shown to be involved in three functional networks: cell cycle, energy metabolism and muscle development. Twenty-two genes were mapped on the pig genome and 12 were found to be located in regions previously reported to contain quantitative trait loci (QTL) affecting pig meat tenderness (chromosomes 2, 6 and 13). Some genes appear therefore as positional candidate genes for QTL.

Nectin-1 is an alphaherpesvirus receptor that binds to virion glycoprotein D (gD). Porcine nectin-1 mediates entry of pseudorabies virus (PRV), herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), and bovine herpesvirus type 1 (BHV-1). The gD-binding domain of nectin-1 is the first or N-terminal immunoglobulin (Ig)-like domain of the entire ectodomain. Here, we generated three transgenic mouse lines expressing a fusion protein consisting of the first Ig-like domain of porcine nectin-1 and the Fc portion of porcine IgG1 to assess the antiviral potential of the first Ig-like domain of nectin-1 in vivo. All of the transgenic mouse lines showed significant resistance to PRV infection via intraperitoneal inoculation (survival rates of 67% to 100%). In the intranasal challenge, a lower but still significant protection was observed; 21% to 55% of the animals from the three transgenic mouse lines survived. The present results demonstrate that a soluble form of the first domain of porcine nectin-1 is able to exert a significant antiviral effect against pseudorabies virus infection.