A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses

<p>Abstract</p> <p>Background</p> <p>Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important.</p> <p>Results</p> <p>A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of <it>n </it>= 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (≤ 8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (<it>MSTN</it>) [<it>P</it>_unadj.= 6.96 × 10^-6]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (<it>P</it>_unadj.= 1.61 × 10^-9; <it>P</it>_Bonf.= 6.58 × 10^-5). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in <it>MSTN </it>associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the <it>MSTN </it>gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (<it>r</it>²= 0.86).</p> <p>Conclusions</p> <p>Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, <it>P </it>= 1.02 × 10^-10; BIEC2-417495, <it>P</it>_unadj.= 1.61 × 10^-9). Functional investigations will be required to determine whether this polymorphism affects putative transcription-factor binding and gives rise to variation in gene and protein expression. Nonetheless, this study demonstrates that the g.66493737C>T SNP provides the most powerful genetic marker for prediction of race distance aptitude in Thoroughbreds.</p

Effects of resistance and all-round, functional training on quality of life, vitality and depression of older adults living in long-term care facilities: a 'randomized' controlled trial [ISRCTN87177281]

BACKGROUND: Regular physical activity may improve different aspects of wellbeing in older people, such as quality of life, vitality and depression. However, there is little experimental evidence to support this assumption. Therefore, we examined the effect of different training protocols on quality of life, vitality and depression of older adults living in long-term care facilities. METHODS: Subjects (n = 173, aged 64 to 94 years, living in long-term care facilities), were randomized to six months of three different moderate-intensity group exercise training protocols, or to an 'educational' control condition. Exercise consisted of two 45–60-minute training sessions per week of 1) resistance training; 2) all-round, functional training; or 3) a combination of both. Perceived health, the Geriatric Depression Scale (GDS), the Vitality Plus Scale (VPS) and the Dementia Quality of Life questionnaire (DQoL) were administered at baseline and after six months. RESULTS: In the combined training group a small but significant decline was seen in perceived health, DQoL and VPS score compared to the control group. CONCLUSIONS: We conclude that neither strength training nor all-round, functional training of moderate intensity is effective in improving quality of life, vitality or depression of older people living in long-term care facilities

Disruption of Autolysis in Bacillus subtilis using TiO2 Nanoparticles

In contrast to many nanotoxicity studies where nanoparticles (NPs) are observed to be toxic or reduce viable cells in a population of bacteria, we observed that increasing concentration of TiO(2) NPs increased the cell survival of Bacillus subtilis in autolysis-inducing buffer by 0.5 to 5 orders of magnitude over an 8 hour exposure. Molecular investigations revealed that TiO(2) NPs prevent or delay cell autolysis, an important survival and growth-regulating process in bacterial populations. Overall, the results suggest two potential mechanisms for the disruption of autolysis by TiO(2) NPs in a concentration dependent manner: (i) directly, through TiO(2) NP deposition on the cell wall, delaying the collapse of the protonmotive-force and preventing the onset of autolysis; and (ii) indirectly, through adsorption of autolysins on TiO(2) NP, limiting the activity of released autolysins and preventing further lytic activity. Enhanced darkfield microscopy coupled to hyperspectral analysis was used to map TiO(2) deposition on B. subtilis cell walls and released enzymes, supporting both mechanisms of autolysis interference. The disruption of autolysis in B. subtilis cultures by TiO(2) NPs suggests the mechanisms and kinetics of cell death may be influenced by nano-scale metal oxide materials, which are abundant in natural systems