![]() Genetic variability of Viola calaminaria, an endemic metallophyte.Bizoux, Jean-Philippe ; Mahy, Grégory ![]() Poster (2004) Detailed reference viewed: 5 (0 ULg) Genetic variance in environmental sensitivity for milk and milk quality in Walloon Holstein cattleVandenplas, Jérémie ; Bastin, Catherine ; Gengler, Nicolas et alin Book of Abstracts of the 63rd Annual Meeting of the European Federation of Animal Science (2012) Detailed reference viewed: 26 (6 ULg) Genetic variance in environmental sensitivity for milk and milk quality in Walloon Holstein cattleVandenplas, Jérémie ; Bastin, Catherine ; Gengler, Nicolas et alConference (2012, August 27) Animals that are robust to environmental changes are desirable in the current dairy industry. This difference in environmental sensitivity can be studied through the heterogeneity of residual variance ... [more ▼] Animals that are robust to environmental changes are desirable in the current dairy industry. This difference in environmental sensitivity can be studied through the heterogeneity of residual variance while homogeneous residual variance between animals is usually assumed homogeneous in traditional genetic evaluations. The aim of this study was to study genetic heterogeneity of residual variance by the estimation of variance components in residual variance for 5 milk and milk quality traits. 146,027 test-day records from 26,887 Walloon Holstein first-parity cows in 747 herds were available. All cows had at least 3 records and had a known sire. These sires had at least 10 cows with records and each herd x test-day had at least 5 cows. Five traits, milk yield, somatic cell score, and content in milk (g/dL) of oleic acid (C18:1 cis-9), monounsaturated and unsaturated fatty acids, were analyzed separately. Estimation of variance components was performed by running iteratively Expectation Maximization-Restricted Maximum Likelihood algorithm by the implementation of double hierarchical generalized linear models. For all traits, the genetic standard deviation in residual variance (i.e. approximately the genetic coefficient of variation of residual variance) was low and ranged between 0.12 and 0.17. The standard deviations due to herd x test day and permanent environment in residual variance ranged between 0.35 and 0.44 for herd x test-day effect and between 0.55 and 0.96 for permanent environmental effect. This study shows the heterogeneity of residual variance and the existence of some genetic variance in environmental sensitivity for all studied traits in the Walloon Holstein dairy cattle. [less ▲] Detailed reference viewed: 27 (7 ULg) Genetic variants in REC8, RNF212, and PRDM9 influence male recombination in cattle.Sandor, Cynthia ; Li, Wanbo ; Coppieters, Wouter et alin PLoS Genetics (2012), 8(7), 1002854 We use >250,000 cross-over events identified in >10,000 bovine sperm cells to perform an extensive characterization of meiotic recombination in male cattle. We map Quantitative Trait Loci (QTL ... [more ▼] We use >250,000 cross-over events identified in >10,000 bovine sperm cells to perform an extensive characterization of meiotic recombination in male cattle. We map Quantitative Trait Loci (QTL) influencing genome-wide recombination rate, genome-wide hotspot usage, and locus-specific recombination rate. We fine-map three QTL and present strong evidence that genetic variants in REC8 and RNF212 influence genome-wide recombination rate, while genetic variants in PRDM9 influence genome-wide hotspot usage. [less ▲] Detailed reference viewed: 11 (4 ULg) Genetic variation among the geogrtaphic population of the grain aphid, Sitobion avenae (Hemiptera: Aphididae) in China inferred from mitochondrial COI gene sequence; ; et al in Agricultural Sciences in China (2011), 10(7), 1041-1048 Detailed reference viewed: 15 (3 ULg) Genetic variation and evolution in the genus Apodemus (Muridae : Rodentia); ; Michaux, Johan ![]() in Biological Journal of the Linnean Society (2002), 75(3), 395-419 Genetic variation was studied using protein electrophoresis of 28-38 gene loci in 1347 specimens of Apodemus agrarius, A. peninsulac, A. flavicollis, A. sylvaticus, A. alpicola, A. uralensis, A. cf ... [more ▼] Genetic variation was studied using protein electrophoresis of 28-38 gene loci in 1347 specimens of Apodemus agrarius, A. peninsulac, A. flavicollis, A. sylvaticus, A. alpicola, A. uralensis, A. cf. hyrcanicus, A. hermonensis, A. m. mystacinus and A. in. epimelas, representing 121 populations from Europe, the Middle East, and North Africa. Mean values of heterozygosity per locus for each species ranged from 0.02 to 0.04. Mean values of Nei's genetic distance (D) between the taxa ranged from 0.06 (between A. flavicollis and A. alpicola) to 1.34 (between A. uralensis and A. agrarius). The highest values of D were found between A. agrarius and other Apodemus species (0.62-1.34). These values correspond to those generally observed between genera in small mammals. Our data show that A. agrarius and A. peninsulae are sister species, well-differentiated from other taxa. High genetic distance between A. m. mystacinus and A. m. epimelas leads us to consider them distinct species and sister taxa to other Western Palaearctic species of the subgenus Sylvaemus. The data also suggest a recent separation of members of the latter group from a common ancestor, and subsequent rapid radiation, making it difficult to infer phylogenetic relationships. Some taxonomic implications of the results are discussed further. (C) 2002 The Linnean Society of London. [less ▲] Detailed reference viewed: 14 (0 ULg) Genetic variation in heat stress tolerance of Holsteins producing under a continental temperate environmentHammami, Hedi ; Arnould, Valérie ; et alPoster (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 ▲] Detailed reference viewed: 66 (14 ULg) Genetic variation in PLAG1 associates with early life body weight and peripubertal weight and growth in Bos taurus.; ; 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 ▲] Detailed reference viewed: 7 (4 ULg) Genetic variation in the autophagy gene ULK1 and risk of Crohn's disease; ; et al in Inflammatory Bowel Diseases (2011), 17(6), 1392-1397 Detailed reference viewed: 22 (5 ULg) Genetic variation in the familial Mediterranean fever gene (MEFV) and risk for Crohn's disease and ulcerative colitis.; ; Louis, Edouard et alin 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 ▲] Detailed reference viewed: 59 (13 ULg)![]() Genetic variation of the bovine thyroglobulin gene studied at the DNA level.Georges, Michel ; Lequarré, Anne-Sophie ; et alin 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 ▲] Detailed reference viewed: 12 (2 ULg)![]() Genetic variation of Viola calaminaria, an endemic metallophyteBizoux, Jean-Philippe ; Mahy, Grégory ![]() 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 ▲] Detailed reference viewed: 23 (0 ULg) Genetic variation within β3 subunit integrin sequences and rodent species susceptibility to pathogenic hantavirusesPagès, Marie ; ; et alConference (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 ▲] Detailed reference viewed: 16 (1 ULg) Genetic, molecular and clinical features of familial isolated pituitary adenomas.Daly, Adrian ; ; Beckers, Albert ![]() 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 ▲] Detailed reference viewed: 9 (4 ULg) Genetical control of sympodial growth and flowering in tomatoThouet, Johanna ; Ormenese, Sandra ; Périlleux, Claire ![]() in Comparative Biochemistry & Physiology Part A : Molecular & Integrative Physiology (2006), 143(4), 170-171 Detailed reference viewed: 27 (7 ULg)![]() Genetical metabolomics of flavonoid biosynthesis in Populus: a case study; ; et al in Plant Journal (2006), 47(2), 224-237 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 ▲] Detailed reference viewed: 2 (0 ULg) Genetical metabolomics of flavonoid biosynthesis in Populus: a case study.; ; et al in Plant Journal : for Cell & Molecular Biology (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 ▲] Detailed reference viewed: 4 (0 ULg) Genetically engineered polypeptides as a new tool for inorganic nano-particles separation in water based mediaVreuls, Christelle ; Genin, Alexis ; Zocchi, Germaine et alin 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 ▲] Detailed reference viewed: 59 (21 ULg) The Genetically Modified Food and The Seven Focus Groups : a Belgian Reflexive Fairy-tale Through The Precautionary PrincipleBrunet, Sébastien ![]() Conference (2000) Detailed reference viewed: 44 (8 ULg) Genetics and genomics of energy balance measured in milk using mid-infrared spectroscopy; ; et al in Book of Abstracts of the 63rd Annual Meeting of the European Federation of Animal Science (2012, August) Detailed reference viewed: 14 (2 ULg) |
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