UK Health and Environment Research Institute

Dogs, domesticated from gray wolves over 15,000 yr ago, exhibit extensive variation among breeds, including differences in olfactory ability. To investigate the genetic basis of these differences, we analyzed single-nucleotide variants (SNVs) in 3 chemosensory receptor gene families—olfactory receptors (ORs), vomeronasal receptors type 1 (V1Rs), and bitter taste receptors (T2Rs)—using whole-genome data from the Dog Biomedical Variant Database Consortium, which includes 635 domestic dogs representing 121 breeds and 8 wolves. We identified 179 segregating pseudogenes in OR genes (minor allele frequency > 1%), including cases where intact genes are pseudogenized in some individuals and vice versa. The number of functional OR genes varied substantially among individuals (779 to 807), while V1R and T2R gene counts were nearly invariant (8 and 16, respectively). Compared to wolves, dogs exhibited significantly higher ratios of nonsynonymous to synonymous SNVs (N/S) in OR and T2R genes, suggesting relaxed functional constraints potentially associated with domestication. Among breeds, Pugs had significantly fewer functional OR genes and a higher N/S ratio than other breeds, even after accounting for copy number variation. Notably, an OR gene orthologous to the human androstenone receptor, OR7D4, was completely pseudogenized in all Pugs but remained largely functional in other breeds. These findings support the hypothesis that reduced olfactory ability in brachycephalic breeds, such as Pugs, is associated with genetic degeneration of OR genes. Overall, our study provides new insights into the genetic diversity of chemosensory receptor repertoires in dogs and underscores the impact of domestication and breed-specific morphological traits on olfactory function.

The oral sugar test (OST) is used to identify equine insulin dysregulation (ID); however only a dose of 0.15 mL/kg bwt corn syrup has been evaluated. To determine the effect of varying the dose of corn syrup on insulin and glucose response to the OST and the test's ability to distinguish between ponies with a history of laminitis (PL) and without laminitis (NL). Randomised crossover experiment. After an overnight fast, in a three-way randomised crossover study with a 7-day washout, 0.15, 0.3 or 0.45 mL/kg bwt corn syrup was administered orally to eight ponies (5 PL and 3 NL) and blood obtained between 0 and 120 min. Serum [insulin] and [glucose] were measured using previously validated radioimmunoassay and colorimetric assays respectively. The repeatability of and the effect of continued pasture access on the dose that best distinguished PL and NL ponies were then assessed. The effect of dose, laminitis history and fasting on serum [insulin] and [glucose] responses were assessed using mixed-effects models. The serum [insulin] following 0.15 mL/kg bwt were not significantly different from 0.3 mL/kg bwt at any time point, while serum [insulin] following 0.45 mL/kg bwt significantly (P<0.01) differed from 0.15 and 0.3 mL/kg bwt at all time points apart from 0 min. The serum [insulin] concentration significantly (P<0.01) differed between NL (mean 86 [95% CI 59, 113] μiu/mL) and PL (146 [95% CI 124, 167] μiu/mL) only following 0.45 mL/kg bwt at 60 min. Repeatability of serum [insulin] at 60 min following 0.45 mL/kg bwt dose under fasted conditions was 0.51. Using AUC insulin improved repeatability to 0.83. There was no significant difference between the fasted and at pasture results. The OST was performed in small numbers of ponies on limited occasions. A dose of 0.45 mL/kg bwt corn syrup may be preferable to differentiate PL and NL ponies.

To determine the prevalence of obesity within a population of pleasure horses and ponies in Victoria, Australia, and to compare owners' perceptions of their animals' body condition with researchers' assessments. An observational study plus owner questionnaire. Ten Pony Club rallies in different regions of Victoria were attended. Information regarding 229 horses and ponies were obtained from owner questionnaires, and owners' perceptions of the current body condition of their animals were assessed using a visual analogue scale. Body condition score (BCS) was assessed by the researchers using the modified Henneke method. The prevalence of researcher-assessed obesity (BCS ≥7/9) in the total surveyed population was 23.1%. A higher prevalence of obesity was identified in Shetland ponies (71.5%) and other pony types (32.0%) compared with horse breeds (9.3%). Owners perceived their animals to be in significantly lower body condition compared with the researchers' assessments (P < 0.001). Although the overall prevalence of obesity within Australian pleasure horses and ponies was 24.5%, a considerably higher proportion of pony breeds fell into this category. Owners frequently underestimated their own animal's body condition. Knowing the prevalence of obesity in this population and understanding how owners perceive the body condition of their animals may help with targeting education around preventative health care, with the aim of reducing the risk of conditions such as insulin dysregulation and laminitis.

Atrial fibrillation (AF) is the most common sustained arrhythmia in the general population. As an age-related arrhythmia AF is becoming a huge socio-economic burden for European healthcare systems. Despite significant progress in our understanding of the pathophysiology of AF, therapeutic strategies for AF have not changed substantially and the major challenges in the management of AF are still unmet. This lack of progress may be related to the multifactorial pathogenesis of atrial remodelling and AF that hampers the identification of causative pathophysiological alterations in individual patients. Also, again new mechanisms have been identified and the relative contribution of these mechanisms still has to be established. In November 2010, the European Union launched the large collaborative project EUTRAF (European Network of Translational Research in Atrial Fibrillation) to address these challenges. The main aims of EUTRAF are to study the main mechanisms of initiation and perpetuation of AF, to identify the molecular alterations underlying atrial remodelling, to develop markers allowing to monitor this processes, and suggest strategies to treat AF based on insights in newly defined disease mechanisms. This article reports on the objectives, the structure, and initial results of this network.