Evani M Viegas-Péquignot

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The recessive autosomal disorder known as ICF syndrome (for immunodeficiency, centromere instability and facial anomalies; Mendelian Inheritance in Man number 242860) is characterized by variable reductions in serum immunoglobulin levels which cause most ICF patients to succumb to infectious diseases before adulthood. Mild facial anomalies include(More)
Full-term development has now been achieved in several mammalian species by transfer of somatic nuclei into enucleated oocytes [1, 2]. Although a high proportion of such reconstructed embryos can evolve until the blastocyst stage, only a few percent develop into live offspring, which often exhibit developmental abnormalities [3, 4]. Regulatory epigenetic(More)
BACKGROUND Genomic imprinting refers to an epigenetic marking resulting in monoallelic gene expression and has a critical role in fetal development. Various imprinting diseases have recently been reported in humans and animals born after the use of assisted reproductive technology (ART). All the epimutations implicated involve a loss of methylation of the(More)
Replication times for all important chromosome bands, of both types R and Q (277 structures) are analysed. — The R-bands form a group of structures whose DNA replicates during the early S-phase, while the DNA situated in the Q-bands replicates during the late S-phase. — There may not exist overlapping between replication times of these two types of(More)
ICF syndrome has been described as the association of variable immunodeficiency, facial anomalies and centromeric heterochromatin instability. Since the chromosome rearrangements seen in cells of ICF patients are reminiscent of the chromosomal changes induced by the undermethylating agent 5-azacytidine in the late S-phase, we have analyzed the methylation(More)
We now report a mutation in the nuclear–encoded flavoprotein (Fp) subunit gene of the succinate dehydrogenase (SDH) in two siblings with complex II deficiency presenting as Leigh syndrome. Both patients were homozygous for an Arg554Trp substitution in the Fp subunit. Their parents (first cousins) were heterozygous for the mutation that occurred in a(More)
We have identified a novel human gene of the Ig superfamily, designated LAG-3. Expression of this gene is undetectable in resting PBL, while it is found (a 2-kb message) in activated T and NK cells. The LAG-3 gene includes eight exons; the corresponding cDNA encodes a 498-amino acid membrane protein with four extracellular IgSF domains. The first one(More)
DNA methylation patterns were evaluated during preimplantation mouse development by analyzing the binding of monoclonal antibody to 5-methylcytosine (5-MeC) on metaphase chromosomes. Specific chromosome patterns were observed in each cell stage. A banding pattern predominated in chromosomes at the one-cell stage. Banding was replaced at the two-cell stage(More)
The genomic DNA is methylated by de novo methyltransferases Dnmt3a and Dnmt3b during early embryonic development. The establishment of appropriate methylation patterns depends on a fine regulation of the methyltransferase activity. The activity of both enzymes increases in the presence of Dnmt3L, a Dnmt3a/3b-like protein. However, it is unclear how the(More)
We have investigated the distribution of DNA methylation in chromosomes and nuclei of normal individuals and ICF (Immunodeficiency, Centromeric instability and Facial abnormalities) syndrome patients, using 5-methylcytosine monoclonal antibody. In this syndrome, DNA digestion with methyl-sensitive enzymes has previously shown a specific hypomethylation of(More)