Number of vertebrae is associated with body size and meat productivity in pigs. The aim of this study was to identify QTL and associated positional candidate genes affecting the number of thoracic vertebrae (THO). A genomewide association study was conducted in a large resource population derived from an F intercross between Landrace and Korean native pigs using the Porcine SNP 60K BeadChip and the genomewide complex trait analysis (GCTA) program based on a linear mixed-effects model. A total of 38,385 SNP markers from 1,105 F progeny were analyzed for the THO trait after filtering for quality control. A total of 90 genomewide significant SNP markers ( < 1.30 × 10) on SSC 7 covering a 20-Mb region were identified for THO in this study. Several previous studies also mapped QTL for vertebral numbers in this region. The strongest association signals were detected at ASGA0035500 (-value = 4.46 × 10; 103,574,383 bp) and DIAS0000795 (-value = 4.46 × 10; 103,594,753 bp). The QTL region on SSC 7 for THO encompasses and , which are previously described candidate genes for vertebral number variation. To refine the QTL region, a haplotype-based linkage and linkage disequilibrium (LALD) analysis using the DualPHASE program was applied because subsequent conditional association and haplotype block analyses could not resolve the region that contains the 2 loci. The LALD analysis refined the critical region to a 533.9-kb region including ; was located outside the critical region. The gene encoding latent transforming growth factor beta binding protein 2 is involved in bone metabolisms. Based on these data, we propose as a positional candidate gene for THO in pigs. After further functional studies and verification of the association in other independent populations, these results could be useful for optimizing breeding programs that improve THO and other economically important traits in pigs.

This study was conducted to compare ozone sensitivity among half-sib families of Japanese red pine (Pinus densiflora S. et. Z). Ninety families were exposed in walk-in type chambers to charcoal-filtered air and 100ppb ozone for eight hours daily over a period of five consecutive months. We surveyed the foliar injury, relative diameter at root collar (DRC) growth, and relative dry weight after fumigation. We selected five tolerant families and five sensitive families. After one year, the selected ten families were exposed to 100ppb ozone for 90 days. Every 30 days after ozone fumigation, the DRC, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were measured. In the earlier stage of ozone fumigation, the tolerant group showed a relative DRC growth rate three times higher than that of the sensitive group. As well, during the entire fumigation period, the growth rate of the tolerant group was superior to that of the sensitive group. Relative SOD activity in the sensitive group was increased 30 days after fumigation, and in accordance with the fumigation period extended it was decreased. MDA content in the ozone treatment manifested at higher levels than in the control group, and the MDA content of the tolerant group manifested at higher levels than that found in the sensitive group. The tolerant group has more antioxidative activity than the sensitive group; therefore the tolerant group can restrain lipid peroxidation and other adverse effects on physiological activity. Ozone-induced growth reduction may thus be decreased in the tolerant group.