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See detailGenetic variation in heat stress tolerance of Holsteins producing under a continental temperate environment
Hammami, Hedi ULg; Arnould, Valérie ULg; Bormann, Jeanne et al

Poster (2012)

Under projected climate changes, considerations for heat stress tolerance but also for genotype by environment interactions should enter breeding decisions, both for importing, but also exporting ... [more ▼]

Under projected climate changes, considerations for heat stress tolerance but also for genotype by environment interactions should enter breeding decisions, both for importing, but also exporting countries. Most studies concerning the breeding strategies on heat stress tolerance used the temperature humidity index (THI) to assess the thermal stress in a given environment and assumed a specific threshold to each studied population with the same response to each individual above this threshold. Recently new comprehensive thermal indices (TI) integrating radiation solar, wind speed, in addition to temperature and relative humidity were developed. Therefore, the aim of this study is advanced modelling of milk yield trait to evaluate the genetic variation in heat stress tolerance of Holsteins in a temperate environment using random regressions models and six new comprehensive TI. A total of 107,350 test day milk records were available for 12,099 primiparous Holsteins calving from 2000 to 2010. Test-day milk records were merged with meteorological data from 14 public weather stations across Luxembourg. Daily values of 6 new comprehensive TI (3 THI and 3 apparent temperature indices) were calculated by averaging hourly TI over 24 hours. The average distance between herds and their meteorological reference station was of 16 km. Sensitivity of cows to the climate environmental conditions was modelled by applying a reaction norm for each animal, representing its EBV for milk yield on values of the TI on the day in milk (DIM). Six separate random regression models were applied using time-dependent (DIM) and specific TI-dependent covariates. Random effects were additive genetic, permanent environmental, and herd year modelled with Legendre polynomials of order 2 for both DIM and TI. Genetic variances of the different TI evaluated in this study represent 27 to 30% of their correspondent variances for DIM effect. Permanent environmental and genetic variances of TI effect were in the same range. Additive genetic variances and heritabilities for daily milk yield slightly decreased with increasing degrees of the different THI and apparent temperature indices. The average daily milk heritability overall the lactation at the mean of each of the six TI was of 0.28. Genetic correlations between adjacent points across the lactation were > 0.90. Correlations between extreme distant DIM (e.g. early and late lactation stage) were reduced at 0.38 to 0.52. The overall genetic correlations between the different values of each TI remain high (> 0.85). EBV’s summing regular additive effect (DIM effect) and tolerance to heat stress (TI effect) were computed for several combinations of DIM and TI values. Ranking for sires and cows did not change among the 6 heat stress indicators. The correlations between EBVs estimated with the six models were greater than 0.90. In conclusion, the different models depicted genetic variation of milk yield among combinations of DIM and TI levels without defining thresholds in advance. Genetic variation was slightly lower when TI values exceed the thermoneutral zone. Breeding for reduced thermal sensitivity using any of the six indicators of heat stress evaluated in this study is possible. The indicator TI2 representing the adjusted THI for radiation solar and wind speed is favoured because it was the indicator that did identify the highest yearly milk losses under this continental temperate environment. [less ▲]

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See detailGenetic variation in PLAG1 associates with early life body weight and peripubertal weight and growth in Bos taurus.
Littlejohn, M.; Grala, T.; Sanders, K. et al

in Animal Genetics (2012), 43(5), 591-4

Variation at the pleiomorphic adenoma gene 1 (PLAG1) locus has recently been implicated in the regulation of stature and weight in Bos taurus. Using a population of 942 outbred Holstein-Friesian dairy ... [more ▼]

Variation at the pleiomorphic adenoma gene 1 (PLAG1) locus has recently been implicated in the regulation of stature and weight in Bos taurus. Using a population of 942 outbred Holstein-Friesian dairy calves, we report confirmation of this effect, demonstrating strong association of early life body weight with PLAG1 genotype. Peripubertal body weight and growth rate were also significantly associated with PLAG1 genotype. Growth rate per kilogram of body weight, daily feed intake, gross feed efficiency and residual feed intake were not significantly associated with PLAG1 genotype. This study supports the status of PLAG1 as a key regulator of mammalian growth. Further, the data indicate the utility of PLAG1 polymorphisms for the selection of animals to achieve enhanced weight gain or conversely to aid the selection of animals with lower mature body weight and thus lower maintenance energy requirements. [less ▲]

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See detailGenetic variation in the autophagy gene ULK1 and risk of Crohn's disease
Henckaerts, Liesbeth; Cleynen, Isabelle; Brinar, Marko et al

in Inflammatory Bowel Diseases (2011), 17(6), 1392-1397

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See detailGenetic variation in the familial Mediterranean fever gene (MEFV) and risk for Crohn's disease and ulcerative colitis.
Villani, Alexandra-Chloé; Lemire, Mathieu; Louis, Edouard ULg et al

in PLoS ONE (2009), 4(9), 7154

BACKGROUND AND AIMS: The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has ... [more ▼]

BACKGROUND AND AIMS: The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene. METHODOLOGY AND RESULTS: MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele. CONCLUSION: The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility. [less ▲]

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See detailGenetic variation of the bovine thyroglobulin gene studied at the DNA level.
Georges, Michel ULg; Lequarré, Anne-Sophie ULg; Hanset, R. et al

in Animal Genetics (1987), 18(1), 41-50

The bovine thyroglobulin gene has been analysed for variation using restriction endonucleases. Six independent restriction fragment length polymorphisms have been identified. One of these results most ... [more ▼]

The bovine thyroglobulin gene has been analysed for variation using restriction endonucleases. Six independent restriction fragment length polymorphisms have been identified. One of these results most probably from a 2.5-kb deletion, the others being compatible with point mutations. We determined that an individual taken at random within the Belgian White and Blue breed is, on average, heterozygous for one out of 1700 nucleotides within the thyroglobulin gene. [less ▲]

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See detailGenetic variation of Viola calaminaria, an endemic metallophyte
Bizoux, Jean-Philippe ULg; Mahy, Grégory ULg

in Proceedings of the GfÖ: Lanscapes, ecosystems and populations: dynamics, functions and conservation (2005)

The zinc violet, Viola calaminaria (DC) Lej., is a rare threatened species in Belgium which is endemic to metalliferous sites. Yours aims were to assess the genetic structure of the species at the scale ... [more ▼]

The zinc violet, Viola calaminaria (DC) Lej., is a rare threatened species in Belgium which is endemic to metalliferous sites. Yours aims were to assess the genetic structure of the species at the scale of its distribution range, including differentiation with related taxa Viola guesphalica and to examine the influence of population size and recent colonisation events on population genetic structure in order to identify conservation priorities. The analysis of genetic variation (Amova) showed a strong population differentiation (Fst = 0.26) with a regional group differentiation. The V. guestfalica population exhibits the larger differentiation (Fst = 0.19). The levels of population genetic diversity (Hs) varied from 0.21 to 0.29. Mean genetic differentiation among ancient populations (Fst =0.26) is higher than genetic differentiation among recent populations (Fst =0.18) while any difference appears on genetic diversity. This strong population differentiation suggests a low gene flow between populations but sufficient within population to maintain high level of diversity. For management, the result implies a hierarchical conservation strategy including small population. New populations had as much genetically importance than old populations. No foundation effects were detected in the recent populations. These populations probably result from multiple colonization effects from more than one source population. Finally, even if some V. calaminaria populations exhibit a similar level of genetic differentiation of V. guestfalica population, this one appeared as a particular genetic pool. [less ▲]

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See detailGenetic variation within β3 subunit integrin sequences and rodent species susceptibility to pathogenic hantaviruses
Pagès, Marie ULg; Tatard, Caroline; Galan, Maxime et al

Conference (2010, April)

Recent investigations in rodent systematics and epidemiology have led to the discovery of numerous Hantavirus species in Asia. As seroprevalences are very low, the screening of thousands of rodents is ... [more ▼]

Recent investigations in rodent systematics and epidemiology have led to the discovery of numerous Hantavirus species in Asia. As seroprevalences are very low, the screening of thousands of rodents is required to genetically identify these hantaviruses and to determine their human pathogenesis as well as their rodent reservoirs. Pathogenic and non-pathogenic hantaviruses use different integrin receptors to enter cells. In particular, human integrins αIIaβ3 and αvβ3 can mediate cellular entry of hemorragic fever with renal syndrome (HFRS)- and hemorragic pulmonary syndrome (HPS)-causing hantaviruses. In contrast, non-pathogenic or low pathogenic hantaviruses were demonstrated to enter the cell via integrin αvβ1. We tested the hypothesis that amino-acid variation in β3 subunit integrin sequences could provide keys to determine a priori the possibility for a rodent species to carry a human pathogenic hantavirus. We sequenced 330 bp of the β3 chain integrin encompassing the Plexin-Semaphorin-Integrin domain, for 63 individuals corresponding to 14 Asian rodent species. We found 65 variable sites and a high level of divergence between species (up to 12%). Although the genetic variation reflected the neutral phylogeny of these species, we found one site differing between rodent species carrying pathogenic hantaviruses and non reservoir rodent species. We also detected another variable site that could be under positive selection, but only in rodent species that do not carry pathogenic hantaviruses. This site did not exhibit any genetic variation in rodent species that carry hantaviruses. In consequence, it is likely that knowing the amino-acid present at this position for a given rodent species could help us determining a priori whether this species is a reservoir of pathogenic hantaviruses. Further investigations are required to examine whether amino-acid changes at these residues could mediate conformational changes that would prevent the fixation of pathogenic hantaviruses. [less ▲]

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See detailGenetic variations in toll-like receptor pathway and lung function decline in Cystic fibrosis patients.
Haerynck, F.; Mahachie John, Jestinah ULg; Van Steen, Kristel ULg et al

in Human immunology (2013), 74(12), 1649-55

The toll-like receptor (TLR) family maintains pulmonary homeostasis by pathogen recognition, clearance and regulation of inflammation. Genes affecting inflammation response play a key role in modifying ... [more ▼]

The toll-like receptor (TLR) family maintains pulmonary homeostasis by pathogen recognition, clearance and regulation of inflammation. Genes affecting inflammation response play a key role in modifying Cystic fibrosis (CF) lung disease severity. We assessed the impact of single nucleotide polymorphisms (SNPs) of TLR genes (TLR1 to TLR10, CD14, lipopolyssacharide-binding protein (LBP)) on lung function in CF patients. Each SNP was tested for time-dependent effect on FEV1, using six genetic models. In addition, we investigated associations between SNP genotypes and extreme subject specific slopes of FEV1 decline. Variant alleles of polymorphisms of TLR2 rs1898830, rs5743708, and rs3804100 demonstrated a consistent association with lung disease severity (p = 0.008, p = 0.006 and p = 0.029 respectively). Patients homozygous for variant C allele of TLR5 polymorphism rs5744174 are more frequently associated with extreme fast FEV1 decline (OR: 20 (95% Confidence Interval:1.85-216.18)). Patients homozygous AA for TLR1 polymorphism rs5743551 are more frequently associated with faster decline of FEV1 compared to heterozygous genotype (OR:7.33 (95% CI:1.63-33.11). Our findings indicate that variations in TLR1, TLR2 and TLR5 genes may influence CF lung function decline. Further functional analysis is required to provide new insights into the pathogenesis of TLRs in CF lung disease severity. [less ▲]

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See detailGenetic, molecular and clinical features of familial isolated pituitary adenomas.
Daly, Adrian ULg; Tichomirowa, M. A.; Beckers, Albert ULg

in Hormone Research (2009), 71(Suppl 2), 116-122

Pituitary adenomas occur in a familial setting in about 5% of all cases, and over half of these are due to multiple endocrine neoplasia type 1 (MEN1) and Carney's complex (CNC). Non-MEN1/CNC familial ... [more ▼]

Pituitary adenomas occur in a familial setting in about 5% of all cases, and over half of these are due to multiple endocrine neoplasia type 1 (MEN1) and Carney's complex (CNC). Non-MEN1/CNC familial pituitary tumours of all tumour phenotypes, known as familial isolated pituitary adenomas (FIPA), were first described in the late 1990s. Clinical features of FIPA differ from those of sporadic pituitary adenomas, as patients with FIPA have a younger age at diagnosis and larger tumours. About 15% of patients with FIPA have mutations in the aryl hydrocarbon receptor-interacting protein gene (AIP), which indicates that FIPA may have a diverse genetic pathophysiology. This article describes the clinical features of FIPA, the tumour pathologies found in this setting and the genetic/molecular data that have recently been reported in FIPA. [less ▲]

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See detailGenetical control of sympodial growth and flowering in tomato
Thouet, Johanna ULg; Ormenese, Sandra ULg; Périlleux, Claire ULg

in Comparative Biochemistry & Physiology Part A : Molecular & Integrative Physiology (2006), 143(4), 170-171

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See detailGenetical metabolomics of flavonoid biosynthesis in Populus: a case study.
Morreel, Kris; Goeminne, Geert; Storme, Veronique et al

in Plant Journal (The) (2006), 47(2), 224-37

Genetical metabolomics [metabolite profiling combined with quantitative trait locus (QTL) analysis] has been proposed as a new tool to identify loci that control metabolite abundances. This concept was ... [more ▼]

Genetical metabolomics [metabolite profiling combined with quantitative trait locus (QTL) analysis] has been proposed as a new tool to identify loci that control metabolite abundances. This concept was evaluated in a case study with the model tree Populus. Using HPLC, the peak abundances were analyzed of 15 closely related flavonoids present in apical tissues of two full-sib poplar families, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24, and correlation and QTL analysis were used to detect flux control points in flavonoid biosynthesis. Four robust metabolite quantitative trait loci (mQTL), associated with rate-limiting steps in flavonoid biosynthesis, were mapped. Each mQTL was involved in the flux control to one or two flavonoids. Based on the identities of the affected metabolites and the flavonoid pathway structure, a tentative function was assigned to three of these mQTL, and the corresponding candidate genes were mapped. The data indicate that the combination of metabolite profiling with QTL analysis is a valuable tool to identify control points in a complex metabolic pathway of closely related compounds. [less ▲]

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See detailGenetically engineered polypeptides as a new tool for inorganic nano-particles separation in water based media
Vreuls, Christelle ULg; Genin, Alexis ULg; Zocchi, Germaine ULg et al

in Journal of Materials Chemistry (2011), 21

The present paper relates a method for the separation of an insoluble inorganic powder out of a mixture of several insoluble powders with different chemical compositions, using genetically engineered ... [more ▼]

The present paper relates a method for the separation of an insoluble inorganic powder out of a mixture of several insoluble powders with different chemical compositions, using genetically engineered inorganic binding peptides (GEPI). GEPI are small peptides that recognize and specifically bind an inorganic solid material. This GEPI is anchored to magnetic beads for easy recovery of the powder of interest from the mixture. [less ▲]

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See detailGenetics and genomics of energy balance measured in milk using mid-infrared spectroscopy
McParland, Sinead; Calus, Mario; Coffey, Mike et al

Poster (2012, August)

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See detailGenetics and genomics of energy balance measured in milk using mid-infrared spectroscopy
McParland, Sinead; Calus, Mario; Coffey, Mike et al

in Book of Abstracts of the 63rd Annual Meeting of the European Federation of Animal Science (2012, August)

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See detailGenetics and Inflammatory Bowel Disease: From Association Studies to Wide Genome Screen
Louis, Edouard ULg; Belaiche, Jacques ULg

in Acta Gastro-Enterologica Belgica (1997), 60(3, Jul-Sep), 201-3

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See detailThe genetics and molecular biology of mitochondria in Chlamydomonas
Matagne, René-Fernand ULg; Remacle, Claire ULg

in Pandalai, S. (Ed.) Recent Research Development in Plant Biology (2002)

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See detailGenetics and regulation of bacterial virulence: towards the molecular version of Koch's postulates
Mainil, Jacques ULg

Conference given outside the academic context (2005)

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See detailThe Genetics in Cushing syndrome
Vandeva, S.; Daly, Adrian ULg; Vroonen, Laurent ULg et al

in European Neuroendocrine Association - Workshop : Novel experimental data on the pituitary and adrenal tumors responsible for Cushing's syndrome (2009)

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See detailThe genetics in Cushing's syndrome
Beckers, Albert ULg

Scientific conference (2009, December)

Detailed reference viewed: 7 (1 ULg)