References of "Farnir, Frédéric"
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See detailMolecular dissection of a quantitative trait locus: a phenylalanine-to-tyrosine substitution in the transmembrane domain of the bovine growth hormone receptor is associated with a major effect on milk yield and composition.
Blott, Sarah; Kim, Jong-Joo; Moisio, Sirja et al

in Genetics (2003), 163(1), 253-66

We herein report on our efforts to improve the mapping resolution of a QTL with major effect on milk yield and composition that was previously mapped to bovine chromosome 20. By using a denser chromosome ... [more ▼]

We herein report on our efforts to improve the mapping resolution of a QTL with major effect on milk yield and composition that was previously mapped to bovine chromosome 20. By using a denser chromosome 20 marker map and by exploiting linkage disequilibrium using two distinct approaches, we provide strong evidence that a chromosome segment including the gene coding for the growth hormone receptor accounts for at least part of the chromosome 20 QTL effect. By sequencing individuals with known QTL genotype, we identify an F to Y substitution in the transmembrane domain of the growth hormone receptor gene that is associated with a strong effect on milk yield and composition in the general population. [less ▲]

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See detailPositional candidate cloning of a QTL in dairy cattle: Identification of a missense mutation in the bovine DGAT1 gene with major effect on milk yield and composition
Grisart, B.; Coppieters, Wouter ULg; Farnir, Frédéric ULg et al

in Genome Research (2002), 12(2), 222-231

We recently mapped a quantitative trait locus (QTL) with a major effect on milk composition-particularly fat content-to the centromeric end of bovine chromosome 14. We subsequently exploited linkage ... [more ▼]

We recently mapped a quantitative trait locus (QTL) with a major effect on milk composition-particularly fat content-to the centromeric end of bovine chromosome 14. We subsequently exploited linkage disequilibrium to refine the map position of this QTL to a 3-cM chromosome interval bounded by microsatellite markers BULGE13 and BULGE09. We herein report the positional candidate cloning of this QTL, involving (I) the construction of a BAC contig spanning the corresponding marker interval, (2) the demonstration that a very strong candidate gene, acylCoA:diacylglycerol acyltransferase (DGATf), maps to that contig, and (3) the identification of a nonconservative K232A substitution in the DGAT1 gene with a major effect on milk fat content and other milk characteristics. [less ▲]

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See detailSimultaneous mining of linkage and linkage disequilibrium to fine map quantitative trait loci in outbred half-sib pedigrees: Revisiting the location of a quantitative trait locus with major effect on milk production on bovine chromosome 14
Farnir, Frédéric ULg; Grisart, B.; Coppieters, Wouter ULg et al

in Genetics (2002), 161(1), 275-287

A maximum-likelihood QTL mapping method that simultaneously exploits linkage and linkage disequilibrium and that is applicable in outbred half-sib pedigrees is described. The method is applied to fine map ... [more ▼]

A maximum-likelihood QTL mapping method that simultaneously exploits linkage and linkage disequilibrium and that is applicable in outbred half-sib pedigrees is described. The method is applied to fine map a QTL with major effect on milk fat content in a 3-cM marker interval on proximal BTA14. This proximal location is confirmed by applying a haplotype-based association method referred to as recombinant ancestral haplotype analysis. The origin of the discrepancy between the QTL position derived in this work and that of a previous analysis is examined and shown to be due to the existence of distinct marker haplotypes associated with QTL alleles having large substitution effects. [less ▲]

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See detailCell-Mediated Immune Response in Calves to Single-Dose, Trickle, and Challenge Infections with Fasciola Hepatica
Bossaert, K.; Jacquinet, E.; Saunders, J. et al

in Veterinary Parasitology (2000), 88(1-2), 17-34

A peripheral blood mononuclear cell (PBMC) proliferation assay was used to study the cell-mediated immune response in eight calves experimentally infected with Fasciola hepatica. Hypersensitivity-related ... [more ▼]

A peripheral blood mononuclear cell (PBMC) proliferation assay was used to study the cell-mediated immune response in eight calves experimentally infected with Fasciola hepatica. Hypersensitivity-related eosinophil and mast-cell responses were also assessed. The primary infection of 500 metacercariae was administered either as a single-dose or as a trickle infection over a 4-week period. Calves were challenge-infected 4 months later with 100 metacercariae and slaughtered 24 weeks postprimary infection. Skin eosinophil counts (SEC) were determined prior to infection on the basis of the intradermal reaction (IDR) to phytohaemagglutinin (PHA). These counts correlated negatively with the mean fluke length but not with the fluke burden found at necropsy. At the end of the experiment, non-specific (PHA) and specific (excretory-secretory parasite, products, FhESAg, and whole-worm extract, FhSomAg) immediate type hypersensitivity IDR were elicited in contrast to delayed type hypersensitivity (DTH) responses. The SEC correlated with blood eosinophilia but not with parasite parameters. These findings suggest that the eosinophil response does not correlate clearly with the development of resistance to F. hepatica infection in cattle. A specific mononuclear cell response to FhSomAg was detectable as early as 7 days after infection in both infected groups, being significantly higher during the very early migratory phase of the juveniles in the single-dose infected calves than in the trickle infected calves. This response remained significantly higher in infected groups than in the control group throughout the experiment. Challenge elicited a significant proliferative response, less pronounced than after primary infection. No production of gamma-interferon (INF-gamma) was recorded 3 weeks after challenge. At necropsy, the mean number of flukes recovered was similar in both infected groups, suggesting that the rate at which the infection is administrated has no effect on protective immunity. Hepatic lesions, similar in both infected groups, were characterised by marked eosinophil and mast-cell infiltration. Liver biopsies were performed and their diagnostic value is discussed. All results suggest that F. hepatica infection predominantly induces a Type-2 response in cattle, and that this response has little protective effect. [less ▲]

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See detailExtensive Genome-Wide Linkage Disequilibrium in Cattle
Farnir, Frédéric ULg; Coppieters, Wouter ULg; Arranz, J. J. et al

in Genome Research (2000), 10(2), 220-7

A genome-wide linkage disequilibrium (LD) map was generated using microsatellite genotypes (284 autosomal microsatellite loci) of 581 gametes sampled from the dutch black-and-white dairy cattle population ... [more ▼]

A genome-wide linkage disequilibrium (LD) map was generated using microsatellite genotypes (284 autosomal microsatellite loci) of 581 gametes sampled from the dutch black-and-white dairy cattle population. LD was measured between all marker pairs, both syntenic and nonsyntenic. Analysis of syntenic pairs revealed surprisingly high levels of LD that, although more pronounced for closely linked marker pairs, extended over several tens of centimorgan. In addition, significant gametic associations were also shown to be very common between nonsyntenic loci. Simulations using the known genealogies of the studied sample indicate that random drift alone is likely to account for most of the observed disequilibrium. No clear evidence was obtained for a direct effect of selection ("Bulmer effect"). The observation of long range disequilibrium between syntenic loci using low-density marker maps indicates that LD mapping has the potential to be very effective in livestock populations. The frequent occurrence of gametic associations between nonsyntenic loci, however, encourages the combined use of linkage and linkage disequilibrium methods to avoid false positive results when mapping genes in livestock. [less ▲]

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See detailHumoral Immune Response in Calves to Single-Dose, Trickle and Challenge Infections with Fasciola Hepatica
Bossaert, K.; Farnir, Frédéric ULg; Leclipteux, Thierry ULg et al

in Veterinary Parasitology (2000), 87(2-3), 103-23

In cattle experimentally infected with Fasciola hepatica, parasite specific IgG1 and IgG2 responses were studied. Additionally parasite specific IgE production was assessed by the Passive Cutaneous ... [more ▼]

In cattle experimentally infected with Fasciola hepatica, parasite specific IgG1 and IgG2 responses were studied. Additionally parasite specific IgE production was assessed by the Passive Cutaneous Anaphylaxis reaction. The primary infection was administered either as a single-dose or as a trickle infection over a 4-week period. Animals were challenged 4 months later. Titres of IgG1 and IgG2 against excretory-secretory parasite products (FhESAg), and against a whole-worm extract (FhSomAg) were measured by enzyme-linked immunosorbent assay (ELISA) in relation to weight gain, serum hepatic enzyme levels, and fluke infection rate. At necropsy, the mean number of flukes recovered was similar in both infected groups. The two ELISAs specific for bovine IgG1 showed analogous sensitivity and specificity (92% and 94%). Cross-reactivity was observed towards Echinococcus granulosus, Cysticercus tenuicollis, and C. ovis but not towards C. bovis, Cooperia spp., and Ostertagia spp. FhESAg gave rise to apparently more stable specific IgG1 titres as compared to FhSomAg. Mean IgG1 titres were significantly higher in the single-dose-infected group than in the trickle-infected group during the early migratory phase of the infection (week 2 to week 4 (FhSomAg) or week 6 (FhESAg)). IgG2 values were consistently lower than IgG1 levels. The kinetic response of both isotypes yielded a similar pattern. Specific IgE antibodies were detected in cattle of both infected groups from week 2 post-primary infection (PPI) onwards. The mean serum glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (gammaGT) activities were significantly higher in the single-dose-infected group for 3 weeks around peak levels (12-14 weeks PPI and 14-16 weeks PPI for GLDH and gammaGT respectively). Western blotting revealed a major antigenic fraction in FhESAg (26-30 kDa) recognized specifically by sera from F. hepatica infected calves as early as 6-8 weeks PPI. Experimental challenge caused no statistically significant modification of any parameter (IgG1 and IgG2 titres, enzymatic activities, immunoblotting) used to monitor the course of the infection. No correlation was found between fluke size and number, and antibody titres, suggesting that IgG1 production has little protective effect against F. hepatica infection. [less ▲]

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See detailPlasma Myeloperoxidase Level and Polymorphonuclear Leukocyte Activation in Horses Suffering from Large Intestinal Obstruction Requiring Surgery: Preliminary Results
Grulke, Sigrid ULg; Benbarek, Hama; Caudron, I. et al

in Canadian Journal of Veterinary Research = Revue Canadienne de Recherche Vétérinaire (1999), 63(2), 142-7

Myeloperoxidase (MPO) is a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Thanks to a radioimmunoassay of equine myeloperoxidase, the authors have observed a ... [more ▼]

Myeloperoxidase (MPO) is a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Thanks to a radioimmunoassay of equine myeloperoxidase, the authors have observed a significantly higher plasma level of MPO in horses operated for strangulation obstruction of the large intestine (n = 6) than in horses suffering from a non-strangulating displacement of the large intestine (n = 9). For the 2 groups, 3 phases were distinguished: reception (P1), intensive care (P2) and terminal phase (P3). The mean peak values of MPO for these phases were 121.6 ng/mL (P1), 168.6 ng/mL (P2), and 107.0 ng/mL (P3) for the non-strangulating group, and 242.6 ng/mL (P1); 426.0 ng/mL (P2), and 379.5 ng/mL (P3) for the strangulation group. The variations of the mean peak values of plasma MPO were significantly different between the 2 groups and between the different phases. A significant increase of the least square means of MPO was observed between P1 and P2. A significant decrease of the least square means of the number of circulating leukocytes was observed between P1 and P3. Polymorphonuclear neutrophil activation could play a major role in the pathogenesis of acute abdominal disease and endotoxic shock. [less ▲]

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See detailComparison of ventrodorsal and dorsoventral radiographic projections for hip dysplasia diagnosis
Saunders, J.; Godefroid, T.; Snaps, Frédéric ULg et al

in Veterinary Record : Journal of the British Veterinary Association (1999), (145), 109-110

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See detailComparison between ventrodorsal and dorsoventral projections for the diagnosis of hip dysplasia
Saunders, J.; Godefroid, T.; Snaps, Frédéric ULg et al

in Veterinary Record : Journal of the British Veterinary Association (1999), 24

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See detailFine-Mapping of Quantitative Trait Loci by Identity by Descent in Outbred Populations: Application to Milk Production in Dairy Cattle
Riquet, J.; Coppieters, Wouter ULg; Cambisano, Nadine ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (1999), 96(16), 9252-9257

We previously mapped a quantitative trait locus (QTL) affecting milk production to bovine chromosome 14. To refine the map position of this QTL, we have increased the density of the genetic map of ... [more ▼]

We previously mapped a quantitative trait locus (QTL) affecting milk production to bovine chromosome 14. To refine the map position of this QTL, we have increased the density of the genetic map of BTA14q11-16 by addition of nine microsatellites and three single nucleotide polymorphisms. Fine-mapping of the QTL was accomplished by a two-tiered approach. In the first phase, we identified seven sires heterozygous "Qq" for the QTL by marker-assisted segregation analysis in a Holstein-Friesian pedigree comprising 1,158 individuals. In a second phase, we genotyped the seven selected sires for the newly developed high-density marker map and searched for a shared haplotype flanking an hypothetical, identical-by-descent QTL allele with large substitution effect. The seven chromosomes increasing milk fat percentage were indeed shown to carry a common chromosome segment with an estimated size of 5 cM predicted to contain the studied QTL. The same haplotype was shown to be associated with increased fat percentage in the general population as well, providing additional support in favor of the location of the QTL within the corresponding interval. [less ▲]

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See detailPlasma myeloperoxidase level and polymorphonuclear leukocyte activation in horses suffering from large intestinal obstruction requiring surgery: preliminary results.
Grulke, Sigrid ULg; Benbarek, H.; Caudron, I. et al

in Canadian Journal of Veterinary Research = Revue Canadienne de Recherche Vétérinaire (1999), 63(2), 142-7

Myeloperoxidase (MPO) is a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Thanks to a radioimmunoassay of equine myeloperoxidase, the authors have observed a ... [more ▼]

Myeloperoxidase (MPO) is a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Thanks to a radioimmunoassay of equine myeloperoxidase, the authors have observed a significantly higher plasma level of MPO in horses operated for strangulation obstruction of the large intestine (n = 6) than in horses suffering from a non-strangulating displacement of the large intestine (n = 9). For the 2 groups, 3 phases were distinguished: reception (P1), intensive care (P2) and terminal phase (P3). The mean peak values of MPO for these phases were 121.6 ng/mL (P1), 168.6 ng/mL (P2), and 107.0 ng/mL (P3) for the non-strangulating group, and 242.6 ng/mL (P1); 426.0 ng/mL (P2), and 379.5 ng/mL (P3) for the strangulation group. The variations of the mean peak values of plasma MPO were significantly different between the 2 groups and between the different phases. A significant increase of the least square means of MPO was observed between P1 and P2. A significant decrease of the least square means of the number of circulating leukocytes was observed between P1 and P3. Polymorphonuclear neutrophil activation could play a major role in the pathogenesis of acute abdominal disease and endotoxic shock. [less ▲]

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See detailThe great-grand-daughter design: a simple strategy to increase the power of a grand-daughter design for QTL mapping
Coppieters, Wouter ULg; Kvasz, A.; Arranz, J. J. et al

in Genetical Research (1999), 74

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See detailEffects of inhaled dry powderipratropium broide on reconvery from exercise of horses with COPD
Duvivier, Dominique Hannia; Bayly, Warwick M; Votion, Dominique ULg et al

in Equine Veterinary Journal (1999), 31(1), 20-24

The present study evaluated ventilatory, cardiovascular and metabolic parameters during recovery from strenuous exercise in horses suffering from a crisis of chronic obstructive pulmonary disease (COPD ... [more ▼]

The present study evaluated ventilatory, cardiovascular and metabolic parameters during recovery from strenuous exercise in horses suffering from a crisis of chronic obstructive pulmonary disease (COPD) and to determine whether ipratropium dry powder inhalation (DPI) before exercise has an effect on these parameters. When 6 saddle horses, affected with COPD, developed airway obstruction, they inhaled placebo and ipratropium (2400 pghorse), the order being randomly chosen. Pulmonary function tests were then recorded 15 min after inhalation. Following these tests, the horses underwent a strenuous treadmill exercise, followed by a ecovery period that consisted of a 10 min walk. Measurements were made at the first and tenth min of recovery. Respiratory flow, 0 2 and C02 fractions in the respired gas, pleural pressure changes and heart rate were recorded. Arterial and mixed venous blood samples were analysed or gas tensions, haemoglobin and plasma lactate concentrations. Oxygen consumption (Wz), C02 production, tidal volume, alveolar oxygen tension (PAOz), alveolar ventilation, the alveolar-pulmonary capillary oxygen difference ((A-a)dOz) and total pulmonary resistance (RL) were measured. The PA02 was the only parameter significantly improved during recovery following ipratropium DPI. This improvement was not accompanied by evidence of improvement of other ventilatory or cardiorespiratory parameters. The results showed that in horses suffering from a crisis of COPD, recovery is characterised by an exercise-induced bronchodilation. Secondly, ipratropium DPI at a dose of 2400 pghorse is an effective bronchoddator in these horses at rest but it has little effect on the airway calibre during the recovery period. It is suggested that the short term recovery period is still Muenced by exercise-induced adjustments that may exceed the bronchodilatory effect of inhaled ipratropium that are observed before exercise [less ▲]

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See detailUse of Excretory/Secretory Antigens in a Competition Test to Follow the Kinetics of Infection by Fasciola Hepatica in Cattle
Leclipteux, Thierry ULg; Torgerson, P. R.; Doherty, M. L. et al

in Veterinary Parasitology (1998), 77(2-3), 103-14

Eight 16-18-month-old Charolais heifers were experimentally infected with Fasciola hepatica. An antigen competition assay was used to follow the kinetics of the infection and was compared to antibody ... [more ▼]

Eight 16-18-month-old Charolais heifers were experimentally infected with Fasciola hepatica. An antigen competition assay was used to follow the kinetics of the infection and was compared to antibody tires and serum liver enzymes. The antigen competition assay was able to detect the presence of infection as soon as 6 days after the start of the experimental infection which is considerably sooner than other methods. Consequently, this assay would be useful in diagnosing fasciolosis early in the prepatent period. The animals were slaughtered at the end of the experiment, the livers recovered and post-mortem fluke burdens determined. However, only serum liver enzyme levels gave any indication of the intensity of infection in the different animals. [less ▲]

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See detailA Rank-Based Nonparametric Method for Mapping Quantitative Trait Loci in Outbred Half-Sib Pedigrees: Application to Milk Production in a Granddaughter Design
Coppieters, Wouter ULg; Kvasz, A.; Farnir, Frédéric ULg et al

in Genetics (1998), 149(3), 1547-55

We describe the development of a multipoint nonparametric quantitative trait loci mapping method based on the Wilcoxon rank-sum test applicable to outbred half-sib pedigrees. The method has been evaluated ... [more ▼]

We describe the development of a multipoint nonparametric quantitative trait loci mapping method based on the Wilcoxon rank-sum test applicable to outbred half-sib pedigrees. The method has been evaluated on a simulated dataset and its efficiency compared with interval mapping by using regression. It was shown that the rank-based approach is slightly inferior to regression when the residual variance is homoscedastic normal; however, in three out of four other scenarios envisaged, i.e., residual variance heteroscedastic normal, homoscedastic skewed, and homoscedastic positively kurtosed, the latter outperforms the former one. Both methods were applied to a real data set analyzing the effect of bovine chromosome 6 on milk yield and composition by using a 125-cM map comprising 15 microsatellites and a granddaughter design counting 1158 Holstein-Friesian sires. [less ▲]

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See detailTowards interbreed IBD fine mapping of the mh locus: double-muscling in the Asturiana de los Valles breed involves the same locus as in the Belgian Blue cattle breed.
Dunner, S.; Charlier, Carole ULg; Farnir, Frédéric ULg et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (1997), 8(6), 430-5

The Spanish "Asturiana" cattle breed is characterized by the segregation of a genetically determined muscular hypertrophy referred to as double-muscling or "culones". We demonstrate by linkage analysis ... [more ▼]

The Spanish "Asturiana" cattle breed is characterized by the segregation of a genetically determined muscular hypertrophy referred to as double-muscling or "culones". We demonstrate by linkage analysis that this muscular hypertrophy involves the mh locus previously shown to cause double-muscling in the Belgian Blue cattle breed, pointing towards locus homogeneity of this trait across both breeds. Moreover, using a twopoint and multipoint maximum likelihood approach, we show that flanking microsatellite markers are in linkage disequilibrium with the mh locus in both breeds albeit with different alleles. Finally, we discuss how allelic homogeneity across breeds might be exploited to achieve efficient genetic fine-mapping of the mh locus. [less ▲]

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