Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailMutants of Chlamydomonas reinhardtii deficient in mitochondrial complex I: Characterization of two mutations affecting the nd1 coding sequence
Remacle, Claire ULg; Baurain, Denis ULg; Cardol, Pierre ULg et al

in Genetics (2001), 158(3), 1051-60

The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) comprises more than 30 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five ... [more ▼]

The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) comprises more than 30 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components of complex I are coded for by mitochondrial genes. Three mutants deprived of complex I activity and displaying slow growth in the dark were isolated after mutagenic treatment with acriflavine. A genetical analysis demonstrated that two mutations (dum20 and dum25) affect the mitochondrial genome whereas the third mutation (dn26) is of nuclear origin. Recombinational analyses showed that dum20 and dum25 are closely linked on the genetic map of the mitochondrial genome and could affect the nd1 gene. A sequencing analysis confirmed this conclusion: dum20 is a deletion of one T at codon 243 of nd1; dum25 corresponds to a 6-bp deletion that eliminates two amino acids located in a very conserved hydrophilic segment of the protein. [less ▲]

Detailed reference viewed: 11 (6 ULg)
Peer Reviewed
See detailMutation analysis of coding sequences for type I procollagen in individuals with low bone density.
Spotila, L. D.; Colige, Alain ULg; Sereda, L. et al

in Journal of Bone and Mineral Research (1994), 9(6), 923-32

Mutations in one of the two genes encoding type I procollagen (COL1A1 and COL1A2) are frequently the cause of osteogenesis imperfecta (OI), a disorder characterized by brittle bones. Here we tested ... [more ▼]

Mutations in one of the two genes encoding type I procollagen (COL1A1 and COL1A2) are frequently the cause of osteogenesis imperfecta (OI), a disorder characterized by brittle bones. Here we tested whether patients with low bone density also have mutations in these genes. The 26 patients studied had no apparent metabolic bone disease, but most had a positive family history of osteopenia or osteoporosis. Although a diagnosis of OI was considered by the clinician in some cases, the clinical criteria for OI were not satisfied. Our strategy for mutation analysis consisted of PCR amplification of cDNA made to fibroblast mRNA using primers specific for the coding regions of COL1A1 and COL1A2. The PCR products were then sequenced directly with primers located within each PCR product. We found that 3 of 26 patients had mutations that altered the encoded amino acid. One mutation, at position alpha 2(I)-661 has been reported (Spotila et al. 1991 Proc Natl Acad Sci USA PNAS 88:5423). The other 2 patients, who were not related to each other, had a mutation that altered the proline codon at alpha 1(I)-27 to alanine. This mutation was not found in 81 normal individuals or in 37 additional osteopenic individuals. However, its effect on the biologic function of type I collagen, as well as its role in osteopenia, is uncertain. In addition to the two mutations, we found a polymorphism in codon alpha 2(I)-459. Although this polymorphism involved an amino acid substitution, it was present with equal frequency in the patient and the normal population. By analyzing this and previously reported neutral sequence variants in the COL1A2 gene, we determined that all patients expressed both alleles of the COL1A2 gene. The 12 patients who were heterozygous for a COL1A1 neutral sequence variant also expressed both alleles. Here we present all PCR primer and sequencing primer information. The results suggest that surveying a larger group of similarly selected individuals may reveal additional mutations in the COL1A1 or COL1A2 genes. [less ▲]

Detailed reference viewed: 15 (4 ULg)
Full Text
Peer Reviewed
See detailMutation analysis of the MEN1 gene in Belgian patients with multiple endocrine neoplasia type 1 and related diseases.
Poncin, Jacques ULg; Abs, R.; Velkeniers, B. et al

in Human Mutation (1999), 13(1), 54-60

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors in parathyroids, enteropancreatic endocrine tissues, anterior pituitary, and other tissues. The gene ... [more ▼]

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors in parathyroids, enteropancreatic endocrine tissues, anterior pituitary, and other tissues. The gene for MEN1 has recently been cloned and shown to code for a 610-amino acid protein of enigmatic function which probably acts as a tumor suppressor. Several mutations causing the MEN1 phenotype have been recently identified. In order to determine the spectrum of MEN1 gene mutations in a sample of 25 Belgian patients, we have systematically screened the 10 exons and adjacent sequences of the MEN1 gene by means of an automatic sequencing protocol. Twelve different mutations were identified including nonsense, frameshift, splicing, and missense mutations. Two of these mutations (D172Y and 357del4) occurred more than once. A missense mutation was also found in a kindred with familial hyperparathyroidism. We observed no significant correlation between the nature or position of mutation and the clinical status. We have also detected 6 intragenic polymorphisms and DNA sequence variants and have analyzed their frequencies in our population. [less ▲]

Detailed reference viewed: 22 (8 ULg)
See detailMutation analysis of the MEN1 gene in Belgian patients with multiple endocrine neoplasia type I and related diseases
Poncin, Jacques ULg; Abs, R.; Velkeniers, B. et al

in 5th Euroregional Oncology meeting - abstract book (1998)

Detailed reference viewed: 1 (0 ULg)
See detailMutation analysis of the MEN1 gene in Belgian patients with multiple endocrine neoplasia type I and related diseases
Poncin, Jacques ULg; Abs, R.; Velkeniers, B. et al

in IV european Congress of Endocrinology - Abstract book (1998)

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailMutation analysis of the MEN1 gene in multiple endocrine neoplasia type 1, familial acromegaly and familial isolated hyperparathyroidism.
Teh, B. T.; Kytola, S.; Farnebo, F. et al

in Journal of Clinical Endocrinology and Metabolism (1998), 83(8), 2621-2626

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disease characterized by neoplasia of the parathyroid glands, the endocrine pancreas, and the anterior pituitary gland. In addition ... [more ▼]

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disease characterized by neoplasia of the parathyroid glands, the endocrine pancreas, and the anterior pituitary gland. In addition, families with isolated endocrine neoplasia, notably familial isolated hyperparathyroidism (FIHP) and familial acromegaly, have also been reported. However, whether these families constitute MEN 1 variants or separate entities remains speculative as the genetic bases for these diseases are unclear. The gene for MEN 1 has recently been cloned and characterized. Using single strand conformation analysis (SSCA) and sequencing, we performed mutation analysis in: a) a total of 55 MEN 1 families from 7 countries, b) 13 isolated MEN 1 cases without family history of the disease, c) 8 acromegaly families, and d) 4 FIHP families. Mutations were identified in 27 MEN 1 families and 9 isolated cases. The 22 different mutations spread across most of the 9 translated exons and included frameshift (11), nonsense (6), splice (2), missense mutations (2), and in-frame deletions (1). Among the 19 Finnish MEN 1 probands, a 1466del12 mutation was identified in 6 families with identical 11q13 haplotypes and in 2 isolated cases indicating a common founder. One frameshift mutation caused by 359del4 (GTCT) was found in 1 isolated case and 4 kindreds of different origin and haplotypes; this mutation therefore represents a common "warm" spot in the MEN1 gene. By analyzing the DNA of the parents of an isolated case one mutation was confirmed to be de novo. No mutation was found in any of the acromegaly and small FIHP families, suggesting that genetic defects other than the MEN1 gene might be involved and that additional such families need to be analyzed. [less ▲]

Detailed reference viewed: 71 (5 ULg)
Full Text
Peer Reviewed
See detailMutation analysis of the pyruvate dehydrogenase E1 alpha gene in eight patients with a pyruvate dehydrogenase complex deficiency.
Lissens, W.; De Meirleir, L.; Seneca, S. et al

in Human mutation (1996), 7(1), 46-51

Most of the mutations causing deficiency of the pyruvate dehydrogenase (PDH) complex are in the X-linked E1 alpha gene. We have developed a rapid screening method for the detection of mutations in this ... [more ▼]

Most of the mutations causing deficiency of the pyruvate dehydrogenase (PDH) complex are in the X-linked E1 alpha gene. We have developed a rapid screening method for the detection of mutations in this gene using reverse transcription of total RNA, polymerase chain reaction amplification of the whole coding region of the gene and single-strand conformation polymorphism (SSCP) analysis. With this method, we studied eight patients with a PDH complex deficiency, using cultured fibroblasts. In all patients, aberrant SSCP patterns were found and, after sequencing of the corresponding fragments, we were able to identify six new mutations and two mutations already described previously. The mutations are point mutations leading to amino acid substitutions (5) and direct repeat insertions (3). The presence of the mutations was confirmed in genomic fibroblast DNA. The 4 female patients were shown to carry both a normal and a mutated E1 alpha gene. [less ▲]

Detailed reference viewed: 5 (2 ULg)
Full Text
Peer Reviewed
See detailA mutation creating a potential illegitimate microRNA target site in the myostatin gene affects muscularity in sheep.
Clop, Alex; Marcq, Fabienne ULg; Takeda, Haruko ULg et al

in Nature Genetics (2006), 38(7), 813-8

Texel sheep are renowned for their exceptional meatiness. To identify the genes underlying this economically important feature, we performed a whole-genome scan in a Romanov x Texel F2 population. We ... [more ▼]

Texel sheep are renowned for their exceptional meatiness. To identify the genes underlying this economically important feature, we performed a whole-genome scan in a Romanov x Texel F2 population. We mapped a quantitative trait locus with a major effect on muscle mass to chromosome 2 and subsequently fine-mapped it to a chromosome interval encompassing the myostatin (GDF8) gene. We herein demonstrate that the GDF8 allele of Texel sheep is characterized by a G to A transition in the 3' UTR that creates a target site for mir1 and mir206, microRNAs (miRNAs) that are highly expressed in skeletal muscle. This causes translational inhibition of the myostatin gene and hence contributes to the muscular hypertrophy of Texel sheep. Analysis of SNP databases for humans and mice demonstrates that mutations creating or destroying putative miRNA target sites are abundant and might be important effectors of phenotypic variation. [less ▲]

Detailed reference viewed: 49 (6 ULg)
See detailMutation de LH
Beckers, Albert ULg

Scientific conference (2007, June 30)

Detailed reference viewed: 2 (0 ULg)
See detailMutation de LH
Beckers, Albert ULg

Scientific conference (2007, May 26)

Detailed reference viewed: 4 (1 ULg)
Full Text
See detailMutation des systèmes partisans et résultats électoraux : Proportion congrue et gouvernabilité
Verjans, Pierre ULg

in Matagne, Geoffroy; Beaufays, Jean (Eds.) La Belgique en mutation : Systèmes politiques et politiques publiques (1968-2008) (2009)

Detailed reference viewed: 55 (4 ULg)
Full Text
Peer Reviewed
See detailMutation douce de l'enseignant en concepteur-tuteur dans des activités d'apprentissage totalement à distance. Communication présentée au Colloque TICE Méditérannée, Nice
Vandeput, Etienne ULg; Denis, Brigitte ULg

in Actes du colloque TICE Méditérannée (en ligne) (2004, November 26)

Experts in education and communication technology cannot speak about distance learning without calling up the new roles it springs up and the new relationships it generates. Its detractors claim that ... [more ▼]

Experts in education and communication technology cannot speak about distance learning without calling up the new roles it springs up and the new relationships it generates. Its detractors claim that, under these new conditions, this kind of learning requires significant and expansive means unlike a more classical one. Instead of giving up in front of such disheartening elements, the authors have been trying to measure how far a simple distance learning system (i.e. with little human, hardware and software means) can be implemented. In that way, they have been creating a learning environment basically based on a mixture of individual and collaborative works. Owing to both this mixture and the organization structure, the students can reach the fixed learning goals. Through these processes, they try to isolate practices, learners or teaching staff should be inspired by. They should, in that way, evolve slightly from a classical context to the design of learning scripts including efficient tutoring in a distance context. The course described in this paper is called “Analysis of distance learning environments”. The public consists of adults having enrolled for a DES in Education and Training Technology. To conduct this experiment, the authors have been setting themselves some rules and constraints in order to derive a general process that might be applied to various situations. These rules and constraints are very close to the usual learner’s working constraints. Recommendations focus on practices including careful preparation, coordination techniques betweenteachers and learner’s initiation into reflexivity. [less ▲]

Detailed reference viewed: 54 (11 ULg)
See detailMutation du gène AIP dans les FIPA
Beckers, Albert ULg

Scientific conference (2006, December 02)

Detailed reference viewed: 15 (0 ULg)
Peer Reviewed
See detailMutation in exon 5 of bovine prolactin gene is not associated with milk traits in Holstein bulls.
Parmentier, Isabelle; Gengler, Nicolas ULg; Laliberte, P. et al

in ASAS/ADSA Joint Meeting (2000, July)

Detailed reference viewed: 10 (0 ULg)
Peer Reviewed
See detailMutation in exon 5 of bovine prolactin gene is not associated with milk traits in Holstein bulls.
Parmentier, Isabelle; Gengler, Nicolas ULg; Laliberte, P. et al

in Journal of Animal Science (2000), 78(Suppl 1),

Detailed reference viewed: 6 (2 ULg)
Full Text
Peer Reviewed
See detailA mutation in the GTPase domain of the large subunit rRNA is involved in the suppression of a -1T frameshift mutation affecting a mitochondrial gene in Chlamydomonas reinhardtii
Matagne, René-Fernand ULg; Baurain, Denis ULg

in Molecular Genetics & Genomics (2001), 266(1), 103-108

The dum19 mutation isolated in Chlamydomonas reinhardtii is due to the deletion of one T at codon 152 of the mitochondrial cox1 gene sequence. Phenotypically, the dum19 mutant is characterized by a lack ... [more ▼]

The dum19 mutation isolated in Chlamydomonas reinhardtii is due to the deletion of one T at codon 152 of the mitochondrial cox1 gene sequence. Phenotypically, the dum19 mutant is characterized by a lack of cytochrome c oxidase activity and is unable to grow under heterotrophic conditions. A spontaneous pseudo-revertant that grows slowly in the dark was isolated from the dum19 mutant strain. A genetic and molecular analysis allowed us to demonstrate that the revertant phenotype is the consequence of two additional mutations that together act as a frameshift suppressor: an m mutation affecting a mitochondrial gene other than cox1 and an n mutation affecting a nuclear gene. On its own the n mutation does not act as a suppressor, whereas the m mutation very slightly compensates for the effect of the -1T mutation. Sequencing analysis showed that the m mutation affects the GTPase-associated domain of the large subunit (LSU) ofmitochondrial rRNA. Surprisingly, two substitutions, A1090 to G and A1098 to C, were found in the LSU rRNA of the revertant, the latter one being already present in the dum19 mutant strain itself. The A1090 to G substitution is thus involved in the suppression of the frameshift mutation, but it is not clear whether the change at position 1098 is also required for the expression of the suppressed phenotype. To our knowledge, this is the first example of a mutation in the GTPase-associated domain acting as a suppressor of a frameshift mutation. [less ▲]

Detailed reference viewed: 5 (1 ULg)
Full Text
Peer Reviewed
See detailTHE MUTATION LYS234HIS YIELDS A CLASS-A BETA-LACTAMASE WITH A NOVEL PH-DEPENDENCE
BRANNIGAN, J.; Matagne, André ULg; Jacob, Françoise et al

in Biochemical Journal (1991), 278(Part 3), 673-678

The lysine-234 residue is highly conserved in beta-lactamases and in nearly all active-site-serine penicillin-recognizing enzymes. Its replacement by a histidine residue in the Streptomyces albus G class ... [more ▼]

The lysine-234 residue is highly conserved in beta-lactamases and in nearly all active-site-serine penicillin-recognizing enzymes. Its replacement by a histidine residue in the Streptomyces albus G class A beta-lactamase yielded an enzyme the pH-dependence of which was characterized by the appearance of a novel pK, which could be attributed to the newly introduced residue. At low pH, the k(cat.) value for benzylpenicillin was as high as 50 % of that of the wild-type enzyme, demonstrating that an efficient active site was maintained. Both k(cat.) and k(cat.)/K(m) dramatically decreased above pH 6 but the decrease in k(cat.)/K(m) could not be attributed to larger K(m) values. Thus a positive charge on the side chain of residue 234 appears to be more essential for transition-state stabilization than for initial recognition of the substrate ground state. [less ▲]

Detailed reference viewed: 18 (2 ULg)
See detailMutation politiques et socioéconomiques latino-américaines
Santander, Sébastian ULg

Conference given outside the academic context (2009)

Detailed reference viewed: 10 (0 ULg)