Mapping carcass and meat quality QTL on Sus Scrofa chromosome 2 in commercial finishing pigs.

Quantitative trait loci (QTL) affecting carcass and meat quality located on SSC2 were identified using variance component methods. A large number of traits involved in meat and carcass quality was detected in a commercial crossbred population: 1855 pigs sired by 17 boars from a synthetic line, which where homozygous (A/A) for IGF2. Using combined linkage and linkage disequilibrium mapping (LDLA), several QTL significantly affecting loin muscle mass, ham weight and ham muscles (outer ham and knuckle ham) and meat quality traits, such as Minolta-L* and -b*, ultimate pH and Japanese colour score were detected. These results agreed well with previous QTL-studies involving SSC2. Since our study is carried out on crossbreds, different QTL may be segregating in the parental lines. To address this question, we compared models with a single QTL-variance component with models allowing for separate sire and dam QTL-variance components. The same QTL were identified using a single QTL variance component model compared to a model allowing for separate variances with minor differences with respect to QTL location. However, the variance component method made it possible to detect QTL segregating in the paternal line (e.g. HAMB), the maternal lines (e.g. Ham) or in both (e.g. pHu). Combining association and linkage information among haplotypes improved slightly the significance of the QTL compared to an analysis using linkage information only.

Characterization of plant proteins that interact with cowpea mosaic virus '60K' protein in the yeast two-hybrid system.

Cowpea mosaic virus (CPMV) replication occurs in close association with small membranous vesicles in the host cell. The CPMV RNA1-encoded 60 kDa nucleotide-binding protein ('60K') plays a role in the formation of these vesicles. In this study, five cellular proteins were identified that interacted with different domains of 60K using a yeast two-hybrid search of an Arabidopsis cDNA library. Two of these host proteins (termed VAP27-1 and VAP27-2), with high homology to the VAP33 family of SNARE-like proteins from animals, interacted specifically with the C-terminal domain of 60K and upon transient expression colocalized with 60K in CPMV-infected cowpea protoplasts. eEF1-beta, picked up using the central domain of 60K, was also found to colocalize with 60K. The possible role of these host proteins in the viral replicative cycle is discussed.