A timely, user-friendly, and flexible marker-assisted speed congenics method

Mice are the most widely used mammalian animal model worldwide. Their use presents many advantages, including our ability to manipulate their genome. Unfortunately, transgenic mice often need to be introgressed to transfer the transgene of interest in a specific mouse line. This time-consuming process can be shortened using the speed congenics technique. However, the need for a panel of informative markers to evaluate the proportion of donor and receiver genomes in different individuals produced at each generation hinders the utilisation of speed congenics. In this study, we present 255 microsatellites and 10 RFLPs which can be used in 18 marker panels, allowing the easy and fast introgression of genes of interest from three mouse lines commonly used for transgenesis (C57BL/6, 129/Sv and FVB) to six mouse lines relevant for biomedical research (BALB/c, C3H, DBA/1, DBA/2, SJL and SWR/J). In addition, our markers analysis confirmed a recently described lack of isogeny in well-established inbred mouse lines available from commercial breeders.

Patellar Proximo-Distal Displacement following Modified Maquet Technique Is Not Predictive of Patellar Luxation

OBJECTIVE

The aim of this study was to test the low sensitivity of the Allberg and Miles index to the stifle opening angle, evaluate the displacement of the patella after a Modified Maquet Technique using this index and assess the incidence of patellar luxation post-Modified Maquet Technique in dogs.

STUDY DESIGN

 Medical records were reviewed from 2012 to 2017. Allberg Miles index were determined for each stifle pre- and postoperatively, as well as the stifle joint opening of each case. Occurrence of patellar luxation was recorded.

RESULTS

 137 stifles on 116 dogs were reviewed. The stifle opening angle did not influence the Allberg Miles index. Pre- and postoperative index showed a distal displacement of the patella after a Modified Maquet Procedure, especially at 135° of stifle opening angle. Only 1/137 cases demonstrated patellar luxation after the surgery.

CONCLUSION

 Based on our statistical analysis, we were able to conclude that within the maximum stifle opening angle range recorded in our series of cases; the Allberg Miles index variation was not significant. While patellar baja is clearly induced by the Modified Maquet Technique, the latter did not seem to predispose patients to post-operative patellar luxation in our study population.

Characterization of Myeloperoxidase in the Healthy Equine Endometrium

Myeloperoxidase (MPO), as a marker of neutrophil activation, has been associated with equine endometritis. However, in absence of inflammation, MPO is constantly detected in the uterine lumen of estrous mares. The aim of this study was to characterize MPO in the uterus of mares under physiological conditions as a first step to better understand the role of this enzyme in equine reproduction. Total and active MPO concentrations were determined, by ELISA and SIEFED assay, respectively, in low-volume lavages from mares in estrus (n = 26), diestrus (n = 18) and anestrus (n = 8) in absence of endometritis. Immunohistochemical analysis was performed on 21 endometrial biopsies randomly selected: estrus (n = 11), diestrus (n = 6) and anestrus (n = 4). MPO, although mostly enzymatically inactive, was present in highly variable concentrations in uterine lavages in all studied phases, with elevated concentrations in estrus and anestrus, while in diestrus, concentrations were much lower. Intracytoplasmic immunoexpression of MPO was detected in the endometrial epithelial cells, neutrophils and glandular secretions. Maximal expression was observed during estrus in mid and basal glands with a predominant intracytoplasmic apical reinforcement. In diestrus, immunopositive glands were sporadic. In anestrus, only the luminal epithelium showed residual MPO immunostaining. These results confirm a constant presence of MPO in the uterine lumen of mares in absence of inflammation, probably as part of the uterine mucosal immune system, and suggest that endometrial cells are a source of uterine MPO under physiological cyclic conditions.

A High-Quality Genome Assembly of Striped Catfish (Pangasianodon hypophthalmus) Based on Highly Accurate Long-Read HiFi Sequencing Data

The HiFi sequencing technology yields highly accurate long-read data with accuracies greater than 99.9% that can be used to improve results for complex applications such as genome assembly. Our study presents a high-quality chromosome-scale genome assembly of striped catfish (Pangasianodon hypophthalmus), a commercially important species cultured mainly in Vietnam, integrating HiFi reads and Hi-C data. A 788.4 Mb genome containing 381 scaffolds with an N50 length of 21.8 Mb has been obtained from HiFi reads. These scaffolds have been further ordered and clustered into 30 chromosome groups, ranging from 1.4 to 57.6 Mb, based on Hi-C data. The present updated assembly has a contig N50 of 14.7 Mb, representing a 245-fold and 4.2-fold improvement over the previous Illumina and Illumina-Nanopore-Hi-C based version, respectively. In addition, the proportion of repeat elements and BUSCO genes identified in our genome is remarkably higher than in the two previously released striped catfish genomes. These results highlight the power of using HiFi reads to assemble the highly repetitive regions and to improve the quality of genome assembly. The updated, high-quality genome assembled in this work will provide a valuable genomic resource for future population genetics, conservation biology and selective breeding studies of striped catfish.

Salinity significantly affects intestinal microbiota and gene expression in striped catfish juveniles

In the present study, juvenile striped catfish (Pangasianodon hypophthalmus), a freshwater fish species, have been chronically exposed to a salinity gradient from freshwater to 20 psu (practical salinity unit) and were sampled at the beginning (D20) and the end (D34) of exposure. The results revealed that the intestinal microbial profile of striped catfish reared in freshwater conditions were dominated by the phyla Bacteroidetes, Firmicutes, Proteobacteria, and Verrucomicrobia. Alpha diversity measures (observed OTUs (operational taxonomic units), Shannon and Faith's PD (phylogenetic diversity)) showed a decreasing pattern as the salinities increased, except for the phylogenetic diversity at D34, which was showing an opposite trend. Furthermore, the beta diversity between groups was significantly different. Vibrio and Akkermansia genera were affected differentially with increasing salinity, the former being increased while the latter was decreased. The genus Sulfurospirillium was found predominantly in fish submitted to salinity treatments. Regarding the host response, the fish intestine likely contributed to osmoregulation by modifying the expression of osmoregulatory genes such as nka1a, nka1b, slc12a1, slc12a2, cftr, and aqp1, especially in fish exposed to 15 and 20 psu. The expression of heat shock proteins (hsp) hsp60, hsp70, and hsp90 was significantly increased in fish reared in 15 and 20 psu. On the other hand, the expression of pattern recognition receptors (PRRs) were inhibited in fish exposed to 20 psu at D20. In conclusion, the fish intestinal microbiota was significantly disrupted in salinities higher than 10 psu and these effects were proportional to the exposure time. In addition, the modifications of intestinal gene expression related to ion exchange and stressful responses may help the fish to adapt hyperosmotic environment. KEY POINTS: • It is the first study to provide detailed information on the gut microbiota of fish using the amplicon sequencing method. • Salinity environment significantly modified the intestinal microbiota of striped catfish. • Intestinal responses may help the fish adapt to hyperosmotic environment.

Salinity affects growth performance, physiology, immune responses and temperature resistance in striped catfish (Pangasianodon hypophthalmus) during its early life stages

In this study, striped catfish larvae were gradually exposed to the increase of different salinities, and then they reached the levels of 0, 5, 10, 15, and 20 psu after 10 days, followed by heat shock at 39 °C to determine stress tolerance. After the 10-day experiment, the survival rate of fish exposed to the 20 psu treatment was only 28.6 ± 4%, significantly lower than that of the other treatments. The results showed that the osmolality of the whole-body (WB) homogenate was gradually and significantly increased with salinity elevation, except in fish exposed to freshwater and 5 psu treatments, while there were no significant changes in WB Na⁺/K⁺-ATPase activity. Digestive enzymatic activities, i.e., pepsin, α-amylase, alkaline phosphatase, and leucine alanine peptidase (leu-ala) generally increased with salinity, but not aminopeptidase and trypsin. Lysozyme and peroxidase activities increased in fish larvae exposed to 15 and 20 psu. These increases proportionally improved growth performance, with the lowest and the highest final weights observed in fish reared at 0 psu (0.08 ± 0.03 g/larvae) and 20 psu (0.11 ± 0.02 g/larvae), respectively, although the average growth recorded at 20 psu could be biased by the high mortality in this group. Occurrence of skeleton deformities, such as in caudal vertebrae and branchiostegal rays, was significantly higher in fish exposed to the higher osmotic conditions (15.0 ± 1.2% and 10.3 ± 2.1% respectively at 0 psu vs. 31.0 ± 2.9% and 49.0 ± 5.6%, respectively at 15 psu). After the 12.5-h heat shock, survival rates significantly differed between treatments with the highest survival observed in fish submitted to 5 psu (68.9%), followed by those exposed to 0 (27%) and 10 (20%) while all fish died at 15 psu. These findings suggest that the striped catfish larvae could be reared in salinity up to 5 to 10 psu with a higher survival and tolerance to thermal stress when compared to fish maintained in freshwater.

Does radiofrequency with contact force supersede cryoballoon for atrial fibrillation ablation? A one-year follow-up retrospective study

Introduction

If catheter ablation of atrial fibrillation (AF) is now proved to be a safe and superior alternative to antiarrhythmic drugs for maintenance of sinus rhythm and improvement of symptoms, the best transcatheter technique is still a matter of debate. Radiofrequency (RF) and cryoballoon (CRYO) are the principal technologies sharing the spotlight, and several observational studies and RCT have compared both techniques with conflicting results.

Purpose

Current RF catheters now use contact-force technologies to precisely calibrate the energy delivered to tissue, according to the force applied to adjacent tissue in grams, time of contact in seconds and more recently power delivered in watts. The purpose of our study is to evaluate the contribution of this technology in “real life ” conditions and its hypothetical potential to supersede CRYO for the ablation of AF.

Methods

Design and population. We conducted a single center retrospective study, spreading over two years (1st January 2018–30th December 2019) and enrolling 376 patients that underwent a first ablation procedure in this period.

Endpoints. The primary endpoint was a comparison of the rate of AF recurrence for each technique, twelve months after initial procedure, respecting an initial 90 days blanking period.

Recurrence was defined as documented AF, atrial flutter, atrial tachycardia lasting at least 30 seconds (12-lead ECG, holter or telemetry) or 6 minutes (for atrial high rate episode on pacemaker interrogation), and/or the need of a second ablation procedure.

We evaluated secondary efficacy endpoints including death, procedure duration, fluoroscopy time and hospitalization for cardiovascular causes. Complications in direct relation with the initial procedure were the primary safety endpoint. Finally, we studied the impact of five factors on recurrence: temporal pattern of AF, left atrium dimension, arrhythmia duration, body mass index and CHADS2VA2Sc score.

Results

Patients who underwent RF ablation were similar to those who underwent cryoablation except for chronic kidney disease, type 2 diabetes and coronaropathy which were more prevalent in RF group.

We found a trend toward lower incidence of recurrences in the cryoballoon group, despite not statistically significant. Hospitalizations for cardiovascular causes and deaths from any cause were slightly higher in the radiofrequency group. As expected, time of procedure was lower and fluoroscopy time higher in cryoballoon group. Significant association was detected between recurrence and both left atrium diameter and CHADS2VA2Sc score.

Conclusion

In this retrospective study, albeit using latest generation ablation catheters in the two different technics, we found no significant difference in recurrence of AF between radiofrequency and cryoballoon ablation of AF. Left atrium diameter and higher CHADS2VA2Sc score are two predictors of recurrence, easy to use in daily clinical practice.

Funding Acknowledgement

Type of funding sources: None. Baseline characteristics – endpointsPrimary efficacy end point

Optimisation of a PMAxx™-RT-qPCR Assay and the Preceding Extraction Method to Selectively Detect Infectious Murine Norovirus Particles in Mussels

Human noroviruses are a major cause for gastroenteritis outbreaks. Filter-feeding bivalve molluscs, which accumulate noroviruses in their digestive tissues, are a typical vector for human infection. RT-qPCR, the established method for human norovirus detection in food, does not allow discrimination between infectious and non-infectious viruses and can overestimate potentially infectious viral loads. To develop a more accurate method of infectious norovirus load estimation, we combined intercalating agent propidium monoazide (PMAxx™)-pre-treatment with RT-qPCR assay using in vitro-cultivable murine norovirus. Three primer sets targeting different genome regions and diverse amplicon sizes were used to compare one-step amplification of a short genome fragment to three two-step long-range RT-qPCRs (7 kbp, 3.6 kbp and 2.3 kbp amplicons). Following initial assays performed on untreated infectious, heat-, or ultraviolet-inactivated murine noroviruses in PBS suspension, PMAxx™ RT-qPCRs were implemented to detect murine noroviruses subsequent to their extraction from mussel digestive tissues; virus extraction via anionic polymer-coated magnetic beads was compared with the proteinase K-dependent ISO norm. The long-range RT-qPCR process detecting fragments of more than 2.3 kbp allowed accurate estimation of the infectivity of UV-damaged murine noroviruses. While proteinase K extraction limited later estimation of PMAxx™ pre-treatment effects and was found to be unsuited to the assay, magnetic bead-captured murine noroviruses retained their infectivity. Genome copies of heat-inactivated murine noroviruses differed by 2.3 log₁₀ between RT-qPCR and PMAxx™-RT-qPCR analysis in bivalve molluscs, the PMAxx™ pre-treatment allowing a closer approximation of infectious titres. The combination of bead-based virus extraction and PMAxx™ RT-qPCR thus provides a more accurate model for the estimation of noroviral bivalve mollusc contamination than the conjunction of proteinase K extraction and RT-qPCR and has the potential (once validated utilising infectious human norovirus) to provide an added measure of security to food safety authorities in the hazard assessment of potential bivalve mollusc contamination.

The use of germicidal ultraviolet light, vaporised hydrogen peroxide and dry heat to decontaminate face masks and filtering respirators contaminated with an infectious norovirus

In the context of the SARS-CoV-2 pandemic, reuse of surgical masks and filtering facepiece respirators has been recommended. Their reuse necessitates procedures to inactivate contaminating human respiratory and oral pathogens. We previously demonstrated decontamination of masks and respirators contaminated with an infectious SARS-CoV-2 surrogate via ultraviolet germicidal irradiation, vaporised hydrogen peroxide, and use of dry heat. Here, we show that these same methods efficiently inactivate a more resistant, non-enveloped oral virus; decontamination of infectious murine norovirus-contaminated masks and respirators reduced viral titres by over four orders of magnitude on mask or respirator coupons.

Mutation c.307G>A in FUT1 gene has no effect on production performance of Yorkshire pigs in the tropics: the case of Vietnam

The alpha (1) fucosyltransferase gene (FUT1) is a candidate gene for controlling the adhesion of Escherichia coli F18 receptor. Indeed, a single-nucleotide polymorphism, c.307G>A, located in the gene is such that pigs with AA genotype are resistant to entero-toxigenic E. coli F18, whereas those with AG and GG genotypes are sensitive. An experiment was carried out in northern Vietnam from March 2016 to May 2017 to determine FUT1 genotype frequencies and the effect of these genotypes on production performance of Yorkshire pigs. A total of 613 animals were genotyped using polymerase chain reaction – restriction fragment length polymorphism method. The body weights at birth, weaning, initial fattening period, and final fattening period were collected from 611, 516, 479, and 418 animals, respectively, whereas backfat thickness, depth of longissimus dorsi, and lean meat percentage were recorded from 328 animals. The frequencies of FUT1 genotypes were found to be in Hardy–Weinberg equilibrium (P = 0.51). Effect of FUT1 genotype was not observed for all production traits (P > 0.05), whereas final body weight and depth of longissimus dorsi were significantly different between females and males (P < 0.05). These results suggest that selection of Yorkshire pigs resistant to entero-toxigenic E. coli F18 could be effective without adversely affecting average daily gain and lean meat.

Modeling the Growth and Interaction Between Brochothrix thermosphacta, Pseudomonas spp., and Leuconostoc gelidum in Minced Pork Samples

The aim of this study was to obtain the growth parameters of specific spoilage micro-organisms previously isolated in minced pork (MP) samples and to develop a three-spoilage species interaction model under different storage conditions. Naturally contaminated samples were used to validate this approach by considering the effect of the food microbiota. Three groups of bacteria were inoculated on irradiated samples, in mono- and in co-culture experiments (n = 1152): Brochothrix thermosphacta, Leuconostoc gelidum, and Pseudomonas spp. (Pseudomonas fluorescens and Pseudomonas fragi). Samples were stored in two food packaging [food wrap and modified atmosphere packaging (CO2 30%/O2 70%)] at three isothermal conditions (4, 8, and 12°C). Analysis was carried out by using both 16S rRNA gene amplicon sequencing and classical microbiology in order to estimate bacterial counts during the storage period. Growth parameters were obtained by fitting primary (Baranyi) and secondary (square root) models. The food packaging shows the highest impact on bacterial growth rates, which in turn have the strongest influence on the shelf life of food products. Based on these results, a three-spoilage species interaction model was developed by using the modified Jameson-effect model and the Lotka Volterra (prey-predator) model. The modified Jameson-effect model showed slightly better performances, with 40-86% out of the observed counts falling into the Acceptable Simulation Zone (ASZ). It only concerns 14-48% for the prey-predator approach. These results can be explained by the fact that the dynamics of experimental and validation datasets seems to follow a Jameson behavior. On the other hand, the Lotka Volterra model is based on complex interaction factors, which are included in highly variable intervals. More datasets are probably needed to obtained reliable factors, and so better model fittings, especially for three- or more-spoilage species interaction models. Further studies are also needed to better understand the interaction of spoilage bacteria between them and in the presence of natural microbiota.

Two-dimensional speckle tracking echocardiography in goats: repeatability, variability, and validation of the technique using an exercise test and an experimentally induced acute ischemic cardiomyopathy

Background

Two-dimensional speckle tracking (2DST) technique has been validated in numerous animal species, but neither studies of repeatability nor measurements after exercise or in animals with cardiac disease have been reported in goats. Goats are an attractive candidate for animal models in human cardiology because they are easy to handle and have a body and heart size comparable to that of humans. Therefore, the aim of this study was to validate this technique in goats for further clinical and experimental applications in this species.

Results

This study was divided into several steps. First, a standardized echocardiographic protocol was performed and 5 cineloops of a right parasternal short-axis view at papillary muscles level were recorded three times at one-day intervals in ten healthy adult unsedated Saanen goats to test repeatability and variability of 2DST measurements. Then, the same measurements were performed immediately before and after a standardized exercise on treadmill in seven of the goats, and at 24 h after induction of an experimental ischemic cardiomyopathy in five of the goats, to test the reliability of the technique to assess physiological and pathological changes. Average and regional measurements of radial and circumferential strain and strain rate, radial displacement, rotation and rotation rate were obtained. Comparisons were performed using two-way ANOVA (p < 0.05). Caprine 2DST average measurements have demonstrated a good repeatability with a low to moderate variability for all measurements except for the diastolic peaks of the circumferential strain rate, radial strain rate and rotation rate. Segmental 2DST measurements were less repeatable than average measurements. Time effect of two-way ANOVA was significant for anteroseptal segment diastolic peaks measurements, rotation and rotation rate measurements. Overall variability of segmental measurements was moderate or high. Segmental and average peak values obtained after exercise and after myocardial ischemia were significantly different than curves obtained at baseline.

Conclusions

The results of this study are consistent with those previously described in other animal species and humans. 2DST echocardiography is a valid technique to evaluate physiological and pathological changes in myocardial function in goats, despite the technical limitations observed in this species.

Assessment of Spoilage Bacterial Communities in Food Wrap and Modified Atmospheres-Packed Minced Pork Meat Samples by 16S rDNA Metagenetic Analysis

Although several studies have focused on the dynamics of bacterial food community, little is known about the variability of batch production and microbial changes that occur during storage. The aim of the study was to characterize the microbial spoilage community of minced pork meat samples, among different food production and storage, using both 16S rRNA gene sequencing and classical microbiology. Three batches of samples were obtained from four local Belgian facilities (A–D) and stored until shelf life under food wrap (FW) and modified atmosphere packaging (MAP, CO₂ 30%/O₂ 70%), at constant and dynamic temperature. Analysis of 288 samples were performed by 16S rRNA gene sequencing in combination with counts of psychrotrophic and lactic acid bacteria at 22°C. At the first day of storage, different psychrotrophic counts were observed between the four food companies (Kruskal-Wallist test, p-value < 0.05). Results shown that lowest microbial counts were observed at the first day for industries D and A (4.2 ± 0.4 and 5.6 ± 0.1 log CFU/g, respectively), whereas industries B and C showed the highest results (7.5 ± 0.4 and 7.2 ± 0.4 log CFU/g). At the end of the shelf life, psychrotrophic counts for all food companies was over 7.0 log CFU/g. With metagenetics, 48 OTUs were assigned. At the first day, the genus Photobacterium (86.7 and 19.9% for food industries A and C, respectively) and Pseudomonas (38.7 and 25.7% for food companies B and D, respectively) were dominant. During the storage, a total of 12 dominant genera (>5% in relative abundance) were identified in MAP and 7 in FW. Pseudomonas was more present in FW and this genus was potentially replaced by Brochothrix in MAP (two-sided Welch’s t-test, p-value < 0.05). Also, a high Bray-Curtis dissimilarity in genus relative abundance was observed between food companies and batches. Although the bacteria consistently dominated the microbiota in our samples are known, results indicated that bacterial diversity needs to be addressed on the level of food companies, batches variation and food storage conditions. Present data illustrate that the combined approach provides complementary results on microbial dynamics in minced pork meat samples, considering batches and packaging variations.

CSF omeprazole concentration and albumin quotient following high dose intravenous omeprazole in dogs

Clinical signs of syringomyelia and hydrocephalus occur secondary to cerebrospinal fluid (CSF) accumulation within the central nervous system. Omeprazole is recommended to treat these conditions despite little evidence of its capacity to decrease CSF production in the dog. Studies into new treatments are hampered by difficulties in measuring CSF production. The albumin quotient (QAlb), the ratio between CSF and serum albumin concentrations, may reflect CSF production and any decrease in CSF production should be associated with an increase in QAlb. The primary objective of this study was to determine CSF omeprazole concentration after administration of a high intravenous dose of omeprazole and to evaluate its impact on QAlb in the dog. The second aim was to validate QAlb as a surrogate marker of CSF production. Eighteen dogs were included in this prospective crossover placebo-controlled study. Each dog received omeprazole (10 mg/kg), acetazolamide (50 mg/kg) combined with furosemide (1 mg/kg) and saline. Blood and CSF samples were obtained on day 0 and then every 7 days, one hour after drug administration. Omeprazole concentrations (2.0 ± 0.4 μmol/L) reached in CSF after high dose omeprazole were lower than the concentrations previously described as decreasing CSF production in dogs. There was no significant increase in QAlb following administration of acetazolamide/furosemide, prohibiting validation of QAlb as a surrogate marker for CSF production. Several dogs presented transient mild side effects after injection of acetazolamide/furosemide. High dose omeprazole was well tolerated in all dogs.

Aggregation of experts: an application in the field of "interactomics" (detection of interactions on the basis of genomic data)

Background

Despite the successful mapping of genes involved in the determinism of numerous traits, a large part of the genetic variation remains unexplained. A possible explanation is that the simple models used in many studies might not properly fit the actual underlying situations. Consequently, various methods have attempted to deal with the simultaneous mapping of genomic regions, assuming that these regions might interact, leading to a complex determinism for various traits. Despite some successes, no gold standard methodology has emerged. Actually, combining several interaction mapping methods might be a better strategy, leading to positive results over a larger set of situations. Our work is a step in that direction.

Results

We first have demonstrated why aggregating results from several distinct methods might increase the statistical power while controlling the type I error. We have illustrated the approach using 6 existing methods (namely: MDR, Boost, BHIT, KNN-MDR, MegaSNPHunter and AntEpiSeeker) on simulated and real data sets. We have used a very simple aggregation strategy: a majority vote across the best loci combinations identified by the individual methods. In order to assess the performances of our aggregation approach in problems where most individual methods tend to fail, we have simulated difficult situations where no marginal effects of individual genes exist and where genetic heterogeneity is present. we have also demonstrated the use of the strategy on real data, using a WTCCC dataset on rheumatoid arthritis.

Since we have been using simplistic assumptions to infer the expected power of the aggregation method, the actual power we estimated from our simulations has turned out to be a bit smaller than theoretically expected. Results nevertheless have shown that grouping the results of several methods is advantageous in terms of power, accuracy and type I error control. Furthermore, as more methods should become available in the future, using a grouping strategy will become more advantageous since adding more methods seems to improve the performances of the aggregated method.

Conclusions

The aggregation of methods as a tool to detect genetic interactions is a potentially useful addition to the arsenal used in complex traits analyses.

Electronic supplementary material

The online version of this article (10.1186/s12859-018-2447-0) contains supplementary material, which is available to authorized users.

Altered mitochondrial oxidative phosphorylation capacity in horses suffering from polysaccharide storage myopathy

Polysaccharide storage myopathy (PSSM) is a widely described cause of exertional rhabdomyolysis in horses. Mitochondria play a central role in cellular energetics and are involved in human glycogen storage diseases but their role has been overlooked in equine PSSM. We hypothesized that the mitochondrial function is impaired in the myofibers of PSSM-affected horses. Nine horses with a history of recurrent exercise-associated rhabdomyolysis were tested for the glycogen synthase 1 gene (GYS1) mutation: 5 were tested positive (PSSM group) and 4 were tested negative (horses suffering from rhabdomyolysis of unknown origin, RUO group). Microbiopsies were collected from the gluteus medius (gm) and triceps brachii (tb) muscles of PSSM, RUO and healthy controls (HC) horses and used for histological analysis and for assessment of oxidative phosphorylation (OXPHOS) using high-resolution respirometry. The modification of mitochondrial respiration between HC, PSSM and RUO horses varied according to the muscle and to substrates feeding OXPHOS. In particular, compared to HC horses, the gm muscle of PSSM horses showed decreased OXPHOS- and electron transfer (ET)-capacities in presence of glutamate&malate&succinate. RUO horses showed a higher OXPHOS-capacity (with glutamate&malate) and ET-capacity (with glutamate&malate&succinate) in both muscles in comparison to the PSSM group. When expressed as ratios, our results highlighted a higher contribution of the NADH pathway (feeding electrons into Complex I) to maximal OXPHOS or ET-capacity in both rhabdomyolysis groups compared to the HC. Specific modifications in mitochondrial function might contribute to the pathogenesis of PSSM and of other types of exertional rhabdomyolyses.

Moku Virus in Invasive Asian Hornets, Belgium, 2016

We report the detection of Moku virus in invasive Asian hornets (Vespa velutina nigrithorax) in Belgium. This constitutes an unexpected report of this iflavirus outside Hawaii, USA, where it was recently described in social wasps. Although virulence of Moku virus is unknown, its potential spread raises concern for European honeybee populations.

Effects of a P-class CpG-ODN administered by intramuscular injection on plasma cytokines and on white blood cells of healthy horses

Cytosine-phosphate-guanosine (CpG-ODN) has been described as a potent immunostimulatory agent in different species. No study reported the effect of a P-class CpG when administered systemically in healthy horses. The aim of this study was to evaluate the tolerance and the effect of an intramuscularly administered P-class CpG-ODN on hematology and on plasma cytokines (IFN-α, IL-10, TNF-α, IFN-γ) in 8 healthy horses. Intra-muscular CpG-ODN or placebo (PBS) was administered twice at a 7 days-interval. Groups were inversed after 2 months of washout period. A physical examination, complete blood count (CBC) and plasma cytokine measurements were performed from 2 days before injection up to 21 days after injection. P-class CpG-ODN injection was well tolerated with minor side effects. After the first injection a significant transient drop in circulating total leukocytes, lymphocytes and an increase in monocytes were observed. A transient drop in eosinophils was also noted after each CpG injection. P-class CpG-ODN at a dose of 5 mg did not create major side effects in 7 horses, one horse showed transient pyrexia. A redistribution of white blood cells was observed in horses receiving CpG, but no change in plasma cytokines was observed at the indicated dose, route of administration and sampling times.

Age-based partitioning of individual genomic inbreeding levels in Belgian Blue cattle

Background

Inbreeding coefficients can be estimated either from pedigree data or from genomic data, and with genomic data, they are either global or local (when the linkage map is used). Recently, we developed a new hidden Markov model (HMM) that estimates probabilities of homozygosity-by-descent (HBD) at each marker position and automatically partitions autozygosity in multiple age-related classes (based on the length of HBD segments). Our objectives were to: (1) characterize inbreeding with our model in an intensively selected population such as the Belgian Blue Beef (BBB) cattle breed; (2) compare the properties of the model at different marker densities; and (3) compare our model with other methods.

Results

When using 600 K single nucleotide polymorphisms (SNPs), the inbreeding coefficient (probability of sampling an HBD locus in an individual) was on average 0.303 (ranging from 0.258 to 0.375). HBD-classes associated to historical ancestors (with small segments ≤ 200 kb) accounted for 21.6% of the genome length (71.4% of the total length of the genome in HBD segments), whereas classes associated to more recent ancestors accounted for only 22.6% of the total length of the genome in HBD segments. However, these recent classes presented more individual variation than more ancient classes. Although inbreeding coefficients obtained with low SNP densities (7 and 32 K) were much lower (0.060 and 0.093), they were highly correlated with those obtained at higher density (r = 0.934 and 0.975, respectively), indicating that they captured most of the individual variation. At higher SNP density, smaller HBD segments are identified and, thus, more past generations can be explored. We observed very high correlations between our estimates and those based on homozygosity (r = 0.95) or on runs-of-homozygosity (r = 0.95). As expected, pedigree-based estimates were mainly correlated with recent HBD-classes (r = 0.56).

Conclusions

Although we observed high levels of autozygosity associated with small HBD segments in BBB cattle, recent inbreeding accounted for most of the individual variation. Recent autozygosity can be captured efficiently with low-density SNP arrays and relatively simple models (e.g., two HBD classes). The HMM framework provides local HBD probabilities that are still useful at lower SNP densities.

Electronic supplementary material

The online version of this article (10.1186/s12711-017-0370-x) contains supplementary material, which is available to authorized users.

Corrigendum: Host DNA released by NETosis promotes rhinovirus-induced type-2 allergic asthma exacerbation

This corrects the article DOI: 10.1038/nm.4332.

[Brain abcesses associated with a systemic infection by Nocardia Farcinica]

The prevalence of nocardia infections is increasing because of both improved detection laboratory techniques and a higher number of immunosuppressed patients. We report the case of a patient with brain abcesses resulting from nocardia farcinica cerebral dissemination associated with lung infection, endocarditis and ocular lesions for which we suspected a similar origin. This case gives the opportunity to discuss the main issues of these infections and the current therapeutic guidelines.

Host DNA released by NETosis promotes rhinovirus-induced type-2 allergic asthma exacerbation

Respiratory viral infections represent the most common cause of allergic asthma exacerbations. Amplification of the type-2 immune response is strongly implicated in asthma exacerbation, but how virus infection boosts type-2 responses is poorly understood. We report a significant correlation between the release of host double-stranded DNA (dsDNA) following rhinovirus infection and the exacerbation of type-2 allergic inflammation in humans. In a mouse model of allergic airway hypersensitivity, we show that rhinovirus infection triggers dsDNA release associated with the formation of neutrophil extracellular traps (NETs), known as NETosis. We further demonstrate that inhibiting NETosis by blocking neutrophil elastase or by degrading NETs with DNase protects mice from type-2 immunopathology. Furthermore, the injection of mouse genomic DNA alone is sufficient to recapitulate many features of rhinovirus-induced type-2 immune responses and asthma pathology. Thus, NETosis and its associated extracellular dsDNA contribute to the pathogenesis and may represent potential therapeutic targets of rhinovirus-induced asthma exacerbations.

KNN-MDR: a learning approach for improving interactions mapping performances in genome wide association studies

Background

Finding epistatic interactions in large association studies like genome-wide association studies (GWAS) with the nowadays-available large volume of genomic data is a challenging and largely unsolved issue. Few previous studies could handle genome-wide data due to the intractable difficulties met in searching a combinatorial explosive search space and statistically evaluating epistatic interactions given a limited number of samples. Our work is a contribution to this field. We propose a novel approach combining K-Nearest Neighbors (KNN) and Multi Dimensional Reduction (MDR) methods for detecting gene-gene interactions as a possible alternative to existing algorithms, e especially in situations where the number of involved determinants is high. After describing the approach, a comparison of our method (KNN-MDR) to a set of the other most performing methods (i.e., MDR, BOOST, BHIT, MegaSNPHunter and AntEpiSeeker) is carried on to detect interactions using simulated data as well as real genome-wide data.

Results

Experimental results on both simulated data and real genome-wide data show that KNN-MDR has interesting properties in terms of accuracy and power, and that, in many cases, it significantly outperforms its recent competitors.

Conclusions

The presented methodology (KNN-MDR) is valuable in the context of loci and interactions mapping and can be seen as an interesting addition to the arsenal used in complex traits analyses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-017-1599-7) contains supplementary material, which is available to authorized users.

COMPARISON BETWEEN SEDATION AND GENERAL ANESTHESIA FOR HIGH RESOLUTION COMPUTED TOMOGRAPHIC CHARACTERIZATION OF CANINE IDIOPATHIC PULMONARY FIBROSIS IN WEST HIGHLAND WHITE TERRIERS

Canine idiopathic pulmonary fibrosis is a progressive interstitial lung disease mainly affecting West Highland white terriers. Thoracic high-resolution computed tomographic (T-HRCT) findings for Canine idiopathic pulmonary fibrosis acquired under general anesthesia have been described previously. However, the use of general anesthesia may be contraindicated for some affected dogs. Sedation may allow improved speed and safety, but it is unknown whether sedation would yield similar results in identification and grading of Canine idiopathic pulmonary fibrosis lesions. The aim of this prospective, observational, method-comparison, case-control study was to compare findings from T-HRCT images acquired under sedation versus general anesthesia for West Highland white terriers affected with Canine idiopathic pulmonary fibrosis (n = 11) and age-matched controls (n = 9), using the glossary of terms of the Fleischner Society and a scoring system. Ground-glass opacity was identified in all affected West Highland white terriers for both sedation and general anesthesia acquisitions, although the Ground-glass opacity extent varied significantly between the two acquisitions (P < 0.001). Ground-glass opacity was the sole lesion observed in control dogs (n = 6), but was less extensive compared with affected West Highland white terriers. Identification and grading of a mosaic attenuation pattern differed significantly between acquisitions (P < 0.001). Identification of lesions such as consolidations, nodules, parenchymal and subpleural bands, bronchial wall thickening, and bronchiectasis did not differ between acquisitions. The present study demonstrated that T-HRCT obtained under sedation may provide different information than T-HRCT obtained under general anesthesia for identification and grading of some Canine idiopathic pulmonary fibrosis lesions, but not all of them. These differences should be taken into consideration when general anesthesia is contraindicated and sedation is necessary for evaluating West Highland white terriers with Canine idiopathic pulmonary fibrosis.

Axillary temperature measurement: a less stressful alternative for hospitalised cats?

Rectal temperature measurement (RTM) can promote stress and defensive behaviour in hospitalised cats. The aim of this study was to assess if axillary temperature measurement (ATM) could be a reliable and less stressful alternative for these animals. In this prospective study, paired rectal and axillary temperatures were measured in 42 cats, either by a veterinarian or a student. To assess the impact of these procedures on the cat's stress state, their heart rate was checked and a cat stress score (CSS) was defined and graded from 1 (relaxed) to 5 (terrified). A moderate correlation was found between RTM and ATM (r=0.52; P<0.0001). RTM was on average 0.9 °C (1.6 °F) higher than ATM (P<0.0001), although a wide variation was found in the difference between these two measurements (-2.1 °C to 3.6 °C (-3.8 °F to 6.5 °F)). ATM failed to identify hypothermia in 25 per cent of the cases and hyperthermia in 19 per cent of the cases but may be considered less stressful than RTM. Indeed, RTM induced a mildly greater increase in heart rate (+6 bpm; P=0.01) and in CSS (+0.2; P=0.001) than ATM. The results were not affected by operator type. In conclusion, RTM should remain the standard method to obtain accurate temperatures in cats.

Ectopic Expression of Retrotransposon-Derived PEG11/RTL1 Contributes to the Callipyge Muscular Hypertrophy

The callipyge phenotype is an ovine muscular hypertrophy characterized by polar overdominance: only heterozygous +Mat/CLPGPat animals receiving the CLPG mutation from their father express the phenotype. +Mat/CLPGPat animals are characterized by postnatal, ectopic expression of Delta-like 1 homologue (DLK1) and Paternally expressed gene 11/Retrotransposon-like 1 (PEG11/RTL1) proteins in skeletal muscle. We showed previously in transgenic mice that ectopic expression of DLK1 alone induces a muscular hypertrophy, hence demonstrating a role for DLK1 in determining the callipyge hypertrophy. We herein describe newly generated transgenic mice that ectopically express PEG11 in skeletal muscle, and show that they also exhibit a muscular hypertrophy phenotype. Our data suggest that both DLK1 and PEG11 act together in causing the muscular hypertrophy of callipyge sheep.

Functional analysis of the three HMA4 copies of the metal hyperaccumulator Arabidopsis halleri

In Arabidopsis halleri, the HMA4 gene has an essential function in Zn/Cd hypertolerance and hyperaccumulation by mediating root-to-shoot translocation of metals. Constitutive high expression of AhHMA4 results from a tandem triplication and cis-activation of the promoter of all three copies. The three AhHMA4 copies possess divergent promoter sequences, but highly conserved coding sequences, and display identical expression profiles in the root and shoot vascular system. Here, an AhHMA4::GFP fusion was expressed under the control of each of the three A. halleri HMA4 promoters in a hma2hma4 double mutant of A. thaliana to individually examine the function of each AhHMA4 copy. The protein showed non-polar localization at the plasma membrane of the root pericycle cells of both A. thaliana and A. halleri. The expression of each AhHMA4::GFP copy complemented the severe Zn-deficiency phenotype of the hma2hma4 mutant by restoring root-to-shoot translocation of Zn. However, each copy had a different impact on metal homeostasis in the A. thaliana genetic background: AhHMA4 copies 2 and 3 were more highly expressed and provided higher Zn tolerance in roots and accumulation in shoots than copy 1, and AhHMA4 copy 3 also increased Cd tolerance in roots. These data suggest a certain extent of functional differentiation among the three A. halleri HMA4 copies, stemming from differences in expression levels rather than in expression profile. HMA4 is a key node of the Zn homeostasis network and small changes in expression level can have a major impact on Zn allocation to root or shoot tissues.

Rational development of an attenuated recombinant cyprinid herpesvirus 3 vaccine using prokaryotic mutagenesis and in vivo bioluminescent imaging

Cyprinid herpesvirus 3 (CyHV-3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57. This triple deleted recombinant replicated efficiently in vitro and expressed an in vivo safety/efficacy profile compatible with use as an attenuated vaccine. To determine the role of the double ORF56-57 deletion in the phenotype and to improve further the quality of the vaccine candidate, a series of deleted recombinants was produced and tested in vivo. These experiments led to the selection of a double deleted recombinant lacking ORF56 and ORF57 as a vaccine candidate. The safety and efficacy of this strain were studied using an in vivo bioluminescent imaging system (IVIS), qPCR, and histopathological examination, which demonstrated that it enters fish via skin infection similar to the wild type strain. However, compared to the parental wild type strain, the vaccine candidate replicated at lower levels and spread less efficiently to secondary sites of infection. Transmission experiments allowing water contamination with or without additional physical contact between fish demonstrated that the vaccine candidate has a reduced ability to spread from vaccinated fish to naïve sentinel cohabitants. Finally, IVIS analyses demonstrated that the vaccine candidate induces a protective mucosal immune response at the portal of entry. Thus, the present study is the first to report the rational development of a recombinant attenuated vaccine against CyHV-3 for mass vaccination of carp. We also demonstrated the relevance of the CyHV-3 carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin.

Common carp, and its colorful ornamental variety koi, is one of the most economically valuable species in aquaculture. Since the late 1990s, the common and koi carp culture industries have suffered devastating worldwide losses due to cyprinid herpesvirus 3 (CyHV-3). In the present study, we report the development of an attenuated recombinant vaccine against CyHV-3. Two genes were deleted from the viral genome, leading to a recombinant virus that is no longer capable of causing the disease but can be propagated in cell culture (for vaccine production) and infect fish when added to the water, thereby immunizing the fish. This attenuated recombinant vaccine also had a drastic defect in spreading from vaccinated to non-vaccinated cohabitant fish. The vaccine induced a protective mucosal immune response capable of preventing the entry of virulent CyHV-3 and is compatible with the simultaneous vaccination of a large number of carp by simply immersing the fish in water containing the vaccine. This vaccine represents a promising tool for controlling the most dreadful disease ever encountered by the carp culture industries. In addition, the present study highlights the importance of the CyHV-3 - carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin.

Effect of storage and cooking on the fatty acid profile of omega-3 enriched eggs and pork meat marketed in Belgium

The fatty acids (FA) profile was determined in n-3 enriched (Columbus™) Belgian eggs and pork in order to evaluate to what extent the n-3 fatty acids, which are very sensitive to oxidation, are resistant to storage or cooking. In standard eggs or pork, no change of the fatty acid profile was observed after storage or cooking without culinary fat, as well as in Columbus™ eggs and pork after storage. Some cooking processes (eggs in custard and meat in oven) induced a slight significant loss of n-3 fatty acids in Columbus™ eggs or pork (11.1% in fat from eggs cooked in custard vs. 15.3% in raw Columbus™ eggs and 11.0% in fat from oven cooked meat vs. 11.6% in raw Columbus™ meat). As expected, when Columbus™ pork is cooked with culinary fat, its fatty acid profile is modified according to the nature of the fat used.

Transforming growth factor beta 1 activation, storage, and signaling pathways in idiopathic pulmonary fibrosis in dogs

BACKGROUND

The pathogenesis of idiopathic pulmonary fibrosis (IPF) in dogs is poorly understood. In human, transforming growth factor β1 (TGF-β1) is considered central in the pathogenesis.

OBJECTIVES

To investigate TGF-β1 pathway in IPF.

ANIMALS

Lung tissues from 12 affected and 11 control dogs. Serum from 16 affected West Highland white Terriers (WHWTs) and healthy dogs from predisposed (13 WHWTs, 12 Scottish Terriers and 13 Bichons Frise) and nonpredisposed breeds (10 Whippets, 10 Belgian shepherds, 8 Labradors).

METHODS

In this prospective study, immunohistochemistry was used to evaluate expression and localization of TGF-β1 protein and proteins involved in TGF-β1 signaling (TGF-β receptor type I and phospho-Smad2/3). Pulmonary expression of TGF-β1 and molecules involved in its storage (latent TGF-β binding proteins [LTBP] 1, 2, and 4), activation (ανβ6 and ανβ8 integrins, thrombospondin-1) and signal inhibition (Smad 7) was analyzed by quantitative reverse transcriptase PCR. Circulating TGF-β1 concentration was measured by ELISA.

RESULTS

In IPF, high level of TGF-β1 protein was found in areas of fibrosis, epithelial cells had strong expression of TGF-β receptor type 1 and phospho-Smad2/3, gene expression was decreased for LTBP 4 (P = .009) and β8 integrin (P < .001) and increased for thrombospondin-1 (P = .016); no difference was seen for Smad7, LTBP1 and 2. Serum TGF-β1 concentration was higher in predisposed compared with nonpredisposed breeds (P < .0001).

CONCLUSIONS AND CLINICAL IMPORTANCE

This study identified an enhanced TGF-β1 signaling activity in IPF. TGF-β1 storage and activation proteins with altered expression represent potential therapeutic targets. Higher circulating TGF-β1 concentration in predisposed breeds might partly explain their susceptibility for IPF.

Sensitivity and permissivity of Cyprinus carpio to cyprinid herpesvirus 3 during the early stages of its development: importance of the epidermal mucus as an innate immune barrier

Cyprinid herpesvirus 3 (CyHV-3) causes a lethal disease in common and koi carp (Cyprinus carpio). The present study investigated the ability of CyHV-3 to infect common carp during the early stages of its development (from embryos to fingerlings) after inoculation by immersion in water containing the virus. Fish were inoculated at different times after hatching with a pathogenic recombinant CyHV-3 strain expressing luciferase. The sensitivity and permissivity of carp to CyHV-3 were investigated using in vivo bioluminescence imaging. The susceptibility of carp to CyHV-3 disease was investigated by measuring the survival rate. Carp were sensitive and permissive to CyHV-3 infection and susceptible to CyHV-3 disease at all stages of development, but the sensitivity of the two early developmental stages (embryo and larval stages) was limited compared to later stages. The lower sensitivity observed for the early developmental stages was due to stronger inhibition of viral entry into the host by epidermal mucus. In addition, independent of the developmental stage at which inoculation was performed, the localization of light emission suggested that the skin is the portal of CyHV-3 entry. Taken together, the results of the present study demonstrate that carp are sensitive and permissive to CyHV-3 at all stages of development and confirm that the skin is the major portal of entry after inoculation by immersion in infectious water. The results also stress the role of epidermal mucus as an innate immune barrier against pathogens even and especially at the early stages of development.

Assessment of Toll-like receptor 2, 4 and 9 SNP genotypes in canine sino-nasal aspergillosis

Background

The exact aetiology of canine sino-nasal aspergillosis (SNA) is unknown. In man, dysfunction in innate immunity, particularly in the function of pattern recognition receptors, is implicated in the pathogenesis of inflammatory sino-nasal disease and in fungal diseases. Associations between single nucleotide polymorphisms (SNPs) in Toll-like receptors (TLRs) and these diseases have been identified. Similarly, in dogs SNPs in genes encoding TLRs may be important in the pathogenesis of SNA. The aims of the present study were (1) to identify the presence of non-synonymous SNPs in the coding regions of the TLR2, 4 and 9 genes in dogs suffering from SNA, and (2) to investigate the SNP genotypes in dogs with SNA compared with a control population.

Results

Direct sequencing of nine dogs of various breeds with SNA revealed two non-synonymous SNPs in the coding region of TLR2, eight in TLR4 and four in TLR9. These non-synonymous SNPs were further evaluated in a case-control study of affected Golden Retrievers, Labrador Retrievers, Rottweilers and Beaucerons. Genotyping was performed using a combination of allele-specific primers and hydrolysis probe assays in 31 dogs with SNA and 31controls. No significant difference in minor allele frequency was identified between these groups, for all studied SNPs, in any of the four breeds.

Conclusions

These findings do not support a role for non-synonymous SNPs in the TLR 2, 4 and 9 coding regions in the pathogenesis of canine SNA, but do not exclude a role for innate immunity in the pathogenesis of the disease.

Utilisation of Large White × Mong Cai crossbred sows and Duroc and stress negative Piétrain boars for the production of fattening pigs under household conditions in northern Vietnam

The objective of this study was to compare the effects of Duroc (DU) and stress-negative Piétrain (PI) as terminal sires mated to F1(Large White × Mong Cai) sows (F1) on productivity, carcass characteristics, meat quality, and meat chemical composition under household conditions in Hai Duong province, Vietnam. The reproduction performances were based on 74 litters of 42 F1 sows from 12 households and the semen from 11 Duroc and 10 Piétrain boars. Data on production and carcass traits were collected from 76 DU × F1 and 67 PI × F1 crossbred fattening pigs. Longissimus dorsi samples from 55 DU × F1 and 37 PI × F1 were analysed to determine meat quality and meat chemical composition. The results show that household affected production, carcass, and meat quality traits (P < 0.05) as well as reproduction (weights at birth and weaning, P < 0.01). In contrast, boar breed did not influence (P > 0.06) reproduction traits (except individual weight of pigs born alive and weaned pigs, P < 0.01), production traits, meat chemical composition, or meat quality (except pH at 4 days post mortem, P < 0.05). Lean meat percentage of Piétrain-sired pigs was higher than that of Duroc-sired pigs (P < 0.05). The use of Piétrain boars does not affect reproduction performance, growth rate, or meat quality but does improve lean meat percentage compared with Duroc boars. This suggests that the use of stress-negative Piétrain boars as terminal sires would improve lean meat percentage under household conditions in North Vietnam.

Urodynamic and morphometric characteristics of the lower urogenital tracts of female Beagle littermates during the sexually immature period and first and second estrous cycles

OBJECTIVE

To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods.

ANIMALS

5 female Beagle littermates.

PROCEDURES

Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles.

RESULTS

At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus.

CONCLUSIONS AND CLINICAL RELEVANCE

Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.

Reproductive and productive performances of the stress-negative Piétrain pigs in the tropics: the case of Vietnam

The objective of the present study is to investigate the reproduction, production and semen traits of the stress-negative Piétrain line of pigs in the north of Vietnam, as well as to identify various factors (halothane genotype, generation-origin, parity, sex and month of the year) acting on these traits. The experiment was carried out on a purebred nucleus on Dong Hiep farm, Haiphong province in Vietnam. The reproduction performances and the sperm quality measures were based on 12 sows and 5 boars imported from Belgium as well as on 29 sows and 14 boars born in Vietnam, while the production performances were recorded only from 251 animals born in Vietnam. No significant differences were observed between halothane genotypes of sows for reproduction traits (P > 0.0578). At the age of 7.5 months, bodyweight, backfat thickness and longissimus depth (7.5) of homozygous-dominant pigs were higher (P < 0.05) than in heterozygotes. Homozygous-dominant boars had higher total number of spermatozoa than heterozygote boars (P < 0.05); similarly, Vietnam boars also presented higher total number of spermatozoa values than Belgium boars (P < 0.001). Vietnam sows had longer duration of pregnancy, more piglets born alive and heavier litter weight of weaning than Belgium sows (P < 0.01). Bodyweight at birth, at weaning, at 2, 5.5 and 7.5 months of age increased from the first to third parity (P < 0.05). Gilts had more lean meat than intact boars (P < 0.01). Compared with observations made in temperate countries, the reproduction and production performances, sperm concentration and total number of spermatozoa of stress-negative Piétrain pigs were reduced, whereas lean meat percentage was not affected. This might be due to the different climate, although improving values for animals born in Vietnam might indicate adaptation of the animals and/or of the technicians with that breed. The results support the interest of the use of this new Piétrain line in tropical countries with ecological and climatic conditions similar to Vietnam.

Use of ancestral haplotypes in genome-wide association studies

We herein present a haplotype-based method to perform genome-wide association studies. The method relies on hidden Markov models to describe haplotypes from a population as a mosaic of a set of ancestral haplotypes. For a given position in the genome, haplotypes deriving from the same ancestral haplotype are also likely to carry the same risk alleles. Therefore, the model can be used in several applications such as haplotype reconstruction, imputation, association studies or genomic predictions. We illustrate then the model with two applications: the fine-mapping of a QTL affecting live weight in cattle and association studies in a stratified cattle population. Both applications show the potential of the method and the high linkage disequilibrium between ancestral haplotypes and causative variants.

Repeatability, variability and reference values of pulsed wave Doppler echocardiographic measurements in healthy Saanen goats

Background

Pulsed wave (PW) Doppler echocardiography has become a routine non invasive cardiac diagnostic tool in most species. However, evaluation of intracardiac blood flow requires reference values, which are poorly documented in goats. The aim of this study was to test the repeatability, the variability, and to establish the reference values of PW measurements in healthy adult Saanen goats. Using a standardised PW Doppler echocardiographic protocol, 10 healthy adult unsedated female Saanen goats were investigated three times at one day intervals by the same observer. Mitral, tricuspid, aortic and pulmonary flows were measured from a right parasternal view, and mitral and aortic flows were also measured from a left parasternal view. The difference between left and right side measurements and the intra-observer inter-day repeatability were tested and then the reference values of PW Doppler echocardiographic parameters in healthy adult female Saanen goats were established.

Results

As documented in other species, all caprine PW Doppler parameters demonstrated a poor inter-day repeatability and a moderate variability. Tricuspid and pulmonary flows were best evaluated on the right side whereas mitral and aortic flows were best obtained on the left side, and reference values are reported for healthy adult Saanen goats.

Conclusions

PW Doppler echocardiography allows the measurement of intracardiac blood flow indices in goats. The reference values establishment will help interpreting these indices of cardiac function in clinical cardiac cases and developing animal models for human cardiology research.