The first genome-wide association study concerning idiopathic epilepsy in Petit Basset Griffon Vendeen.

The dog breed Petit Basset Griffon Vendeen has a relatively high prevalence of idiopathic epilepsy compared to other dog breeds and previous studies have suggested a genetic cause of the disease in this breed. Based on these observations, a genome-wide association study was performed to identify possible epilepsy-causing loci. The study included 30 unaffected and 23 affected dogs, genotyping of 170K SNPs, and data analysis using plink and emmax. Suggestive associations at CFA13, CFA24 and CFA35 were identified with markers close to three strong candidate genes. However, subsequent sequencing of exons of the three genes did not reveal sequence variations, which could explain development of the disease. This is, to our knowledge, the first report on loci and genes with a possible connection to idiopathic epilepsy in Petit Basset Griffon Vendeen. However, further studies are needed to conclusively identify the genetic cause of idiopathic epilepsy in this dog breed.

Diet-Dependent Changes of the DNA Methylome Using a Göttingen Minipig Model for Obesity.

Objective: Environmental factors can influence obesity by epigenetic mechanisms. The aim of this study was to investigate obesity-related epigenetic changes and the potential for reversal of these changes in the liver of Göttingen minipigs subjected to diet interventions. Methods: High-throughput liquid hybridization capture-based bisulfite sequencing (LHC-BS) was used to quantify the methylation status of gene promotor regions in liver tissue in three groups of male castrated Göttingen minipigs: a standard chow group (SD, N = 7); a group fed high fat/fructose/cholesterol diet (FFC, N = 10) and a group fed high fat/fructose/cholesterol diet during 7 months and reversed to standard diet for 6 months (FFC/SD, N = 12). Expression profiling by qPCR of selected metabolically relevant genes was performed in liver tissue from all pigs. Results: The pigs in the FFC diet group became morbidly obese. The FFC/SD diet did not result in a complete reversal of the body weight to the same weight as in the SD group, but it resulted in reversal of all lipid related metabolic parameters. Here we identified widespread differences in the patterning of cytosine methylation of promoters between the different feeding groups. By combining detection of differentially methylated genes with a rank-based hypergeometric overlap algorithm, we identified 160 genes showing differential methylation in corresponding promoter regions in the FFC diet group when comparing with both the SD and FFC/SD groups. As expected, this differential methylation under FFC diet intervention induced de-regulation of several metabolically-related genes involved in lipid/cholesterol metabolism, inflammatory response and fibrosis generation. Moreover, five genes, of which one is a fibrosis-related gene (MMP9), were still perturbed after diet reversion. Conclusion: Our findings highlight the potential of exploring diet-epigenome interactions for treatment of obesity.

Unraveling molecular mechanisms involved in the development of leptin resistance using the pig as a model.

The increase in obesity worldwide underlines the need for research concerning its metabolic and genetic determinants. One of the most intriguing mechanisms regarding obesity involves leptin and its signaling cascade. Leptin is a key regulator contributing to the fine-tuned crosstalk between nutrient availability and appetite signaling in the central nervous system. Owing to ethical concerns, many human tissues are not readily available and pigs can serve as a good animal model owing to their comparable anatomy, metabolism and genetics. In the present study, we utilized the pig to investigate the possible impact of increased adiposity on the development of alterations within the leptin signaling pathway. Two divergent groups of pigs (High and Low) were defined based on a high and low amount of mesenteric fat. Cortex, cerebellum, hypothalamus, mesenteric, subcutaneous and retroperitoneal fat tissues were used to study changes in expression levels of 94 mRNA transcripts related to the leptin signaling pathway using the qPCR approach. No significant differences were found at the central nervous system, whereas the expression level of STAT1 was reduced in mesenteric fat and leptin (LEP) and interleukin 6 (IL6) were shown to be consistently increased in all analyzed fat compartments from pigs with a high amount of mesenteric fat. These results could imply the onset of leptin and pro-inflammatory cytokine overexpression at early stages of obesity in the analyzed pigs without affecting any key components in the central nervous system. Thus, these pigs showing a unique leptin deregulation in adipose tissues could be a useful translational resource for studies of obesity and leptin resistance phenotypes.

Validation of DNA test for hip dysplasia failed in Danish Labrador Retrievers.

Canine hip dysplasia is characterized by poor hip joint conformation and laxity. The disease is a complex trait influenced by both genetics and environment. Diagnosis and quantification of hip dysplasia are performed by radiographic examination of the hip joint and the diagnosis is used for making breeding decisions in many breeds. A prognostic genetic test (the Dysgen test) based on seven associated SNPs has been developed in a study based on Spanish Labrador Retrievers. In our study this test has been evaluated in 39 Danish Labrador Retrievers with known radiographic hip score: 14 with hip dysplasia (grade D or E) and 25 without hip dysplasia (grade A or B). There was no significant correlation between the Dysgen test results and the radiographic hip status (P = 0.3203) in these dogs, indicating that Dysgen test results obtained for Danish Labrador Retrievers have no prognostic value.

Analysis of porcine body size variation using re-sequencing data of miniature and large pigs.

BACKGROUND: Domestication has led to substantial phenotypic and genetic variation in domestic animals. In pigs, the size of so called minipigs differs by one order of magnitude compared to breeds of large body size. We used biallelic SNPs identified from re-sequencing data to compare various publicly available wild and domestic populations against two minipig breeds to gain better understanding of the genetic background of the extensive body size variation. We combined two complementary measures, expected heterozygosity and the composite likelihood ratio test implemented in "SweepFinder", to identify signatures of selection in Minipigs. We intersected these sweep regions with a measure of differentiation, namely FST, to remove regions of low variation across pigs. An extraordinary large sweep between 52 and 61 Mb on chromosome X was separately analyzed based on SNP-array data of F2 individuals from a cross of Goettingen Minipigs and large pigs. RESULTS: Selective sweep analysis identified putative sweep regions for growth and subsequent gene annotation provided a comprehensive set of putative candidate genes. A long swept haplotype on chromosome X, descending from the Goettingen Minipig founders was associated with a reduction of adult body length by 3% in F2 cross-breds. CONCLUSION: The resulting set of genes in putative sweep regions implies that the genetic background of body size variation in pigs is polygenic rather than mono- or oligogenic. Identified genes suggest alterations in metabolic functions and a possible insulin resistance to contribute to miniaturization. A size QTL located within the sweep on chromosome X, with an estimated effect of 3% on body length, is comparable to the largest known in pigs or other species. The androgen receptor AR, previously known to influence pig performance and carcass traits, is the most obvious potential candidate gene within this region.

Interbreed variation in serum serotonin (5-hydroxytryptamine) concentration in healthy dogs.

INTRODUCTION: Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds. OBJECTIVE: To investigate potential interbreed variation in serum 5-HT in healthy dogs. ANIMALS: 483 healthy dogs of nine breeds aged 1-7 years. METHODS: Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Median 5-HT concentration was 252.5 (interquartile range = 145.5-390.6) ng/mL. Overall breed difference was found (p<0.0001), and 42% of pairwise breed comparisons were significant. Univariate regression analysis showed association between serum 5-HT concentration and breed, center of examination, storage time, and sex, with higher 5-HT in females. In multiple regression analysis, the final model had an adjusted R2 of 0.27 with breed (p<0.0001), center (p<0.0001), and storage time (p=0.014) remaining significant. Within centers, overall breed differences were found at 3/5 centers (p≤0.028), and pairwise comparisons within those centers showed breed differences in 42% of comparisons. Among the included breeds, Newfoundlands, Belgian Shepherds and CKCSs had highest 5-HT concentrations. CONCLUSIONS: Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1-7 years. These differences should be taken into account when designing clinical studies.

Inotropic and lusitropic effects of levosimendan and milrinone assessed by strain echocardiography-A randomised trial.

BACKGROUND: We compared the direct inotropic and lusitropic effects of two inodilators, milrinone and levosimendan in patients after aortic valve replacement for aortic stenosis. METHODS: In this randomised, blinded study, 31 patients with normal LV function, were randomised to either levosimendan (0.1 and 0.2 µg/kg/min, n = 15) or milrinone (0.4 and 0.8 µg/kg/min, n = 16) after aortic valve replacement. The effects on LV performance, LV strain, systolic (SR-S) and early diastolic (SR-E) strain rate were assessed by a pulmonary artery catheter and transoesophageal two-dimensional speckle tracking echocardiography of the LV inferior wall. To circumvent the inodilator-induced hemodynamic changes on LV systolic and diastolic deformation, central venous pressure (CVP), systolic artery pressure (SAP), and heart rate were maintained constant by colloid infusion, phenylephrine-induced vasoconstriction and atrial pacing, respectively, during drug infusion. RESULTS: Both inotropic agents induced a dose-dependent increase in cardiac index and stroke volume index by approximately 20% at the highest infusion rates with no differences between groups (P = .139 and .249, respectively). CVP, pulmonary capillary wedge pressure, SAP and heart rate were maintained constant in both groups. LV strain and SR-S increased with both agents, dose-dependently, by 17%-18% and 25%-30%, respectively, at the highest infusion rates, with no difference between groups (P = .434 and .284, respectively). Both agents improved early LV relaxation with no differences between groups (P = .637). At the higher doses, both agents increased SR-E by 30%. CONCLUSIONS: At clinically relevant infusion rates and a certain increase in LV performance the direct inotropic and lusitropic of milrinone and levosimendan were comparable.

Identification of the mutation causing progressive retinal atrophy in Old Danish Pointing Dog.

Progressive retinal atrophy (PRA) is a common cause of blindness in many dog breeds. It is most often inherited as a simple Mendelian trait, but great genetic heterogeneity has been demonstrated both within and between breeds. In many breeds the genetic cause of the disease is not known, and until now, the Old Danish Pointing Dog (ODP) has been one of those breeds. ODP is one of the oldest dog breeds in Europe. Seventy years ago the breed almost vanished, but today a population still exists, primarily in Denmark but with some dogs in Germany and Sweden. PRA has been diagnosed in ODP since the late 1990s. It resembles late onset PRA in other dog breeds, and it is inherited as an autosomal recessive trait. In the present study, we performed whole-genome sequencing and identified a single base insertion (c.3149_3150insC) in exon 1 of C17H2orf71. This is the same mutation previously found to cause PRA in Gordon Setters and Irish Setters, and it was later found in Tibetan Terrier, Standard Poodle and the Polski Owczarek Nizinny. The presence of the mutation in such a diverse range of breeds indicates an origin preceding creation of modern dog breeds. Hence, we screened 262 dogs from 44 different breeds plus four crossbred dogs, and can subsequently add Miniature Poodle and another polish sheepdog, the Polski Owczarek Podhalanski, to the list of affected breeds.

A targeted genotyping approach enhances identification of variants in taste receptor and appetite/reward genes of potential functional importance for obesity-related porcine traits.

Taste receptors (TASRs) and appetite and reward (AR) mechanisms influence eating behaviour, which in turn affects food intake and risk of obesity. In a previous study, we used next generation sequencing to identify potentially functional mutations in TASR and AR genes and found indications for genetic associations between identified variants and growth and fat deposition in a subgroup of animals (n = 38) from the UNIK resource pig population. This population was created for studying obesity and obesity-related diseases. In the present study we validated results from our previous study by investigating genetic associations between 24 selected single nucleotide variants in TASR and AR gene variants and 35 phenotypes describing obesity and metabolism in the entire UNIK population (n = 564). Fifteen variants showed significant association with specific obesity-related phenotypes after Bonferroni correction. Six of the 15 genes, namely SIM1, FOS, TAS2R4, TAS2R9, MCHR2 and LEPR, showed good correlation between known biological function and associated phenotype. We verified a genetic association between potentially functional variants in TASR/AR genes and growth/obesity and conclude that the combination of identification of potentially functional variants by next generation sequencing followed by targeted genotyping and association studies is a powerful and cost-effective approach for increasing the power of genetic association studies.

Load-dependence of myocardial deformation variables - a clinical strain-echocardiographic study.

BACKGROUND: The effects of left ventricular (LV) loading on myocardial deformation variables are not well-studied in the clinical setting. In the present study, we evaluated the effects of isolated changes in preload, afterload and heart rate on LV longitudinal strain, systolic (SR-S) and early diastolic strain rate (SR-E) in post-cardiac surgery patients. METHODS: Twenty-one patients were studied early after cardiac surgery. Longitudinal myocardial strain and SR were analysed off-line using 2-D speckle echocardiography. The experimental protocol consisted of three consecutive interventions: (1) preload was increased by passive leg elevation, (2) afterload was increased by an infusion of phenylephrine to increase arterial blood pressure by 10-15% and (3) heart rate was increased 10% and 20% by atrial pacing. During both the preload and afterload challenges heart rate was kept constant by atrial pacing. Central venous pressure was kept constant during pacing by infusion of hetastarch/albumin. RESULTS: The increase in preload increased LV strain, SR-S and SR-E by 20%, 11% and 17%, respectively. The phenylephrine-induced increase in afterload, did not affect LV strain, SR-S or SR-E. LV strain was not affected while SR-S and SR-E increased by pacing-induced heart rate increase. CONCLUSION: After cardiac surgery, systolic and early diastolic strain rate are dependent on both preload and heart rate, while neither of these variables was afterload-dependent. LV strain was preload-dependent but not affected by atrial pacing. When evaluating the direct effects of various pharmacological or other interventions on myocardial contractility and relaxation, preload and heart rate must be controlled.

Circulating let-7g is down-regulated in Bernese Mountain dogs with disseminated histiocytic sarcoma and carcinomas - a prospective study.

Cancer is a prevalent cause of mortality in Bernese mountain dogs (BMDs). Circulating microRNAs (miRNAs) are found in blood and have been identified as promising biomarkers in various neoplastic diseases in humans. In the current study, the expression profile of different types of miRNAs was investigated in healthy BMDs and BMDs with cancer. Seven healthy and six non-treated BMDs with cancer [four with disseminated histiocytic sarcomas (DHS)] were enrolled in this study. Clinical evaluations including physical examination, blood analysis, urinalysis and diagnostic imaging were performed on all dogs. Twenty-four different miRNAs were profiled from RNA isolated from whole blood preserved in PAXgene® tubes using quantitative real-time PCR (qPCR). The miRNA let-7g was significantly down-regulated in dogs with cancer (P = 0.002) and dogs with DHS (P = 0.011) compared with healthy controls. This miRNA is a known tumour suppressor and further analyses are warranted to assess its value as a non-invasive biomarker for early detection of different types of cancer in BMDs.

Effect of Breed on Plasma Endothelin-1 Concentration, Plasma Renin Activity, and Serum Cortisol Concentration in Healthy Dogs.

BACKGROUND: There are breed differences in several blood variables in healthy dogs. OBJECTIVE: Investigate breed variation in plasma endothelin-1 (ET-1) concentration, plasma renin activity, and serum cortisol concentration. ANIMALS: Five-hundred and thirty-one healthy dogs of 9 breeds examined at 5 centers (2-4 breeds/center). METHODS: Prospective observational study. Circulating concentrations of ET-1 and cortisol, and renin activity, were measured using commercially available assays. Absence of organ-related or systemic disease was ensured by thorough clinical investigations, including blood pressure measurement, echocardiography, ECG, blood and urine analysis. RESULTS: Median ET-1 concentration was 1.29 (interquartile range [IQR], 0.97-1.82) pg/mL, median cortisol concentration 46.0 (IQR, 29.0-80.8) nmol/L, and median renin activity 0.73 (IQR, 0.48-1.10) ng/mL/h in all dogs. Overall, breed differences were found in ET-1 and cortisol concentrations, and renin activity (P < .0001 for all). Pair-wise comparisons between breeds differed in 67% of comparisons for ET-1, 22% for cortisol, and 19% for renin activity, respectively. Within centers, breed differences were found at 5/5 centers for ET-1, 4/5 centers for cortisol, and 2/5 centers for renin activity. Newfoundlands had highest median ET-1 concentration, 3 times higher than Cavalier King Charles Spaniels, Doberman Pinschers, and Dachshunds. Median renin activity was highest in Dachshunds, twice the median value in Newfoundlands and Boxers. Median cortisol concentration was highest in Finnish Lapphunds, almost 3 times higher than in Boxers. CONCLUSIONS AND CLINICAL IMPORTANCE: Breed variation might be important to take into consideration when interpreting test results in clinical studies.

The prevalence of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 different dog breeds.

INTRODUCTION: To investigate the prevalence and amplitudes of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 other dog breeds. ANIMALS: Electrocardiograms from 206 healthy dogs representing 11 dog breeds were included in the study. Besides Petit Basset Griffon Vendéen (PBGV; n = 23) 10 other dog breeds were included. MATERIALS AND METHODS: An electrocardiogram ruler was used for measuring the amplitudes of the J waves. The definition of a J wave was a positive deflection at the J point of ≥0.1 mV in more than 1 lead of the bipolar standard limb leads (I, II, III) or the unipolar standard limb leads (aVL and aVF). RESULTS: The prevalence of J waves in the PBGV (n = 23) was 91% (n = 21, standard error (SE) = 5.9%), which was significantly higher compared to seven other dog breeds (p < 0.05). The overall prevalence of J waves in all 11 dog breeds (n = 206) was 43% (n = 89, robust SE = 7.8%). There was no significant difference in the prevalence between male and female dogs (p = 0.79). Neither did age (p = 0.22) nor heart rate (p = 0.25) significantly affect the prevalence of J wave. CONCLUSIONS: The PBGV had the highest prevalence of J waves and the highest amplitudes compared to 10 other dog breeds. However J waves were also seen in other breeds. Therefore, J waves may be considered a normal variant on the canine electrocardiogram and should not be interpreted as cardiac disease.

Discrepancy in compliance between the clinical and genetic diagnosis of choroidal hypoplasia in Danish Rough Collies and Shetland Sheepdogs.

Collie eye anomaly (CEA) is a congenital, inherited ocular disorder which is widespread in herding breeds. Clinically, the two major lesions associated with CEA are choroidal hypoplasia (CH) and coloboma, and both lesions are diagnosed based on ophthalmological examination. A 7.8-kb intronic deletion in the gene encoding non-homologous end-joining factor 1 (NHEJ1) has been reported to be the causative mutation underlying CH when present in the homozygous state. In this study, we have investigated the compliance between the clinical and genetic diagnosis of CH in the Danish Rough Collie and Shetland Sheepdog populations. Our results show that the deletion in NHEJ1 is not predictive for CH in the Danish Rough Collie population, whereas the clinical and genetic diagnosis is in accordance with each other in the Shetland Sheepdog population. Based on these results, it can be concluded that the intronic deletion in NHEJ1 is not the causative mutation but, rather, a marker linked to the locus underlying the trait in some populations but linked to both the wild-type and CH-causing locus in most dogs in the Danish Rough Collie population.

Detection of a quantitative trait locus associated with resistance to infection with Trichuris suis in pigs.

Whipworms (Trichuris spp.) infect a variety of hosts, including domestic animals and humans. Of considerable interest is the porcine whipworm, T. suis, which is particularly prevalent in outdoor production systems. High infection levels may cause growth retardation, anaemia and haemorrhagic diarrhoea. A significant proportion of the variation in Trichuris faecal egg count (FEC) has been attributed to the host's genetic make-up. The aim of the present study was to identify genetic loci associated with resistance to T. suis in pigs. We used single nucleotide polymorphism (SNP) markers to perform a whole-genome scan of an F1 resource population (n = 195) trickle-infected with T. suis. A measured genotype analysis revealed a putative quantitative trait locus (QTL) for T. suis FEC on chromosome 13 covering ∼ 4.5 Mbp, although none of the SNPs reached genome-wide significance. We tested the hypothesis that this region of SSC13 harboured genes with effects on T. suis burden by genotyping three SNPs within the putative QTL in unrelated pigs exposed to either experimental or natural T. suis infections and from which we had FEC (n = 113) or worm counts (n = 178). In these studies, two of the SNPs (rs55618716, ST) were associated with FEC (P < 0.01), thus confirming our initial findings. However, we did not find any of the SNPs to be associated with T. suis worm burden. In conclusion, our study demonstrates that genetic markers for resistance to T. suis as indicated by low FEC can be identified in pigs.

Prevalence and heritability of symptomatic syringomyelia in Cavalier King Charles Spaniels and long-term outcome in symptomatic and asymptomatic littermates.

BACKGROUND: Syringomyelia (SM) is common in the Cavalier King Charles Spaniel (CKCS). Dogs with syringes express clinical signs or might be clinically silent. OBJECTIVES: To investigate the prevalence and heritability of symptomatic SM, the association between clinical signs and magnetic resonance imaging (MRI) findings, and long-term outcome. ANIMALS: All CKCS registered in the Danish Kennel Club in 2001 (n = 240). METHODS: A cross-sectional questionnaire-based prevalence study validated by telephone interviews and clinically investigated clinical signs of SM. Dogs were 6 years at the time of investigation. A prospective observational litter study including clinical investigations, MRI and 5-year follow-up of symptomatic and asymptomatic siblings. Heritability was estimated based on the scale of liability in the study population and litter cohort. RESULTS: The cross-sectional study estimated a prevalence of symptomatic SM at 15.4% in the population. Thirteen symptomatic and 9 asymptomatic siblings participated in the litter study. Spinal cord syringes were confirmed in 21 of 22 littermates (95%). Syrinx diameter and mean syrinx : spinal cord ratio were significantly correlated with clinical signs (P < .01). Estimated heritability of symptomatic SM was 0.81. Symptomatic SM motivated euthanasia in 20%. Dogs with syringes, which expressed no clinical signs at the age of 6, remained asymptomatic in 14/15 cases (93%). CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of symptomatic SM is high and genetics have a high impact on clinical disease expression. Further investigations of factors influencing the outbreak threshold of clinical signs of SM are desirable.

Clinical findings and prevalence of the mutation associated with primary ciliary dyskinesia in Old English Sheepdogs.

BACKGROUND: Primary ciliary dyskinesia (PCD) is generally a recessively inherited disorder characterized by dysfunction of motile cilia. A mutation in a new causative gene (CCDC39) has been identified in the Old English Sheepdog (OES). OBJECTIVES: To describe the clinical findings and the molecular changes of affected dogs and estimate the worldwide prevalence of the mutation in a large cohort of OES. ANIMALS: 578 OES, including 28 affected and 550 clinically healthy dogs. METHODS: This retrospective study reviewed the data of OES diagnosed with PCD and OES tested for the mutation. Clinical data including results of physical examination and further investigations were obtained on 11/28 dogs. CCDC39 expression was assessed by qRT-PCR and Western blot analysis in affected dogs and healthy dogs. DNA was extracted on 561/578 dogs and a genetic test by Taqman technology was developed to genotype the CCDC39 mutation in these dogs. RESULTS: Clinical findings were recurrent nasal discharge and cough, pyrexia, leucocytosis, and bronchopneumonia. Ultrastructural defects were characterized by central microtubular abnormalities and decreased number of inner dynein arms (IDAs). Molecular analysis revealed a reduced expression of CCDC39 RNA and an absence of CCDC39 protein in affected dogs compared to healthy dogs. The mutation was more frequent in nonrandomly selected European OES population with a higher proportion of carriers (19%) compared to non-European dogs (7%). CONCLUSION AND CLINICAL IMPORTANCE: CCDC39 mutation is dispersed in a worldwide population and is responsible for PCD in this breed. Genetic testing might enable control of this disease.

Breed differences in natriuretic peptides in healthy dogs.

BACKGROUND: Measurement of plasma concentration of natriuretic peptides (NPs) is suggested to be of value in diagnosis of cardiac disease in dogs, but many factors other than cardiac status may influence their concentrations. Dog breed potentially is 1 such factor. OBJECTIVE: To investigate breed variation in plasma concentrations of pro-atrial natriuretic peptide 31-67 (proANP 31-67) and N-terminal B-type natriuretic peptide (NT-proBNP) in healthy dogs. ANIMALS: 535 healthy, privately owned dogs of 9 breeds were examined at 5 centers as part of the European Union (EU) LUPA project. METHODS: Absence of cardiovascular disease or other clinically relevant organ-related or systemic disease was ensured by thorough clinical investigation. Plasma concentrations of proANP 31-67 and NT-proBNP were measured by commercially available ELISA assays. RESULTS: Overall significant breed differences were found in proANP 31-67 (P < .0001) and NT-proBNP (P < .0001) concentrations. Pair-wise comparisons between breeds differed in approximately 50% of comparisons for proANP 31-67 as well as NT-proBNP concentrations, both when including all centers and within each center. Interquartile range was large for many breeds, especially for NT-proBNP. Among included breeds, Labrador Retrievers and Newfoundlands had highest median NT-proBNP concentrations with concentrations 3 times as high as those of Dachshunds. German Shepherds and Cavalier King Charles Spaniels had the highest median proANP 31-67 concentrations, twice the median concentration in Doberman Pinschers. CONCLUSIONS AND CLINICAL IMPORTANCE: Considerable interbreed variation in plasma NP concentrations was found in healthy dogs. Intrabreed variation was large in several breeds, especially for NT-proBNP. Additional studies are needed to establish breed-specific reference ranges.

Identifying QTL and genetic correlations between fur quality traits in mink (Neovison vison).

Mapping of QTL affecting fur quality traits (guard hair length, guard hair thickness, density of wool, surface of the fur and quality) and skin length was performed in a three-generation mink population (F2 design). In the parental generation, Nordic Brown mink were crossed reciprocally with American Black short nap mink. In all, 1082 mink encompassing three generations were used for the analyses. The mink were genotyped for 104 microsatellites covering all 14 autosomes. The QTL analyses were performed by least-square regression implemented in gridqtl software. Genetic and phenotypic correlations and heritabilities were estimated using the average information-restricted maximum-likelihood method. Evidence was found for QTL affecting fur quality traits on nine autosomes. QTL were detected for guard hair thickness on chromosomes 1, 2, 3, 6 and 13; for guard hair length on chromosomes 2, 3 and 6; for wool density on chromosomes 6 and 13; for surface on chromosomes 7, 12 and 13; for quality on chromosomes 6, 7, 11 and 13; and for skin length on chromosomes 7 and 9. Proximity of locations of QTL for guard hair length, guard hair thickness and for wool density and quality suggests that some of the traits are in part under the influence of the same genes. Traits under the influence of QTL at close or identical positions also were traits that were strongly genotypically correlated. Based on the results of correlation analyses, the most important single traits influencing the quality were found to be density of wool, guard hair thickness and appearance of the surface.

Expression studies of six human obesity-related genes in seven tissues from divergent pig breeds.

Obesity has reached epidemic proportions globally and has become the cause of several major health risks worldwide. Presently, more than 100 loci have been related to obesity and metabolic traits in humans by genome-wide association studies. The complex genetic architecture behind obesity has triggered a need for the development of better animal models than rodents. The pig has emerged as a very promising biomedical model to study human obesity traits. In this study, we have characterized the expression patterns of six obesity-related genes, leptin (LEP), leptin receptor (LEPR), melanocortin 4 receptor (MC4R), fat mass and obesity associated (FTO), neuronal growth regulator 1 (NEGR)1 and adiponectin (ADIPOQ), in seven obesity-relevant tissues (liver; muscle; pancreas; hypothalamus; and retroperitoneal, subcutaneous and mesenteric adipose tissues) in two pig breeds (production pigs and Göttingen minipigs) that deviate phenotypically and genetically from each other with respect to obesity traits. We observe significant differential expression for LEP, LEPR and ADIPOQ in muscle and in all three adipose tissues. Interestingly, in pancreas, LEP expression is only detected in the fat minipigs. FTO shows significant differential expression in all tissues analyzed, and NEGR1 shows significant differential expression in muscle, pancreas, hypothalamus and subcutaneous adipose tissue. The MC4R transcript can be detected only in hypothalamus. In general, the expression profiles of the investigated genes are in accordance with those observed in human studies. Our study shows that both the differences between the investigated breeds and the phenotypic state with respect to obesity/leanness play a large role for differential expression of the obesity-related genes.