Publications (16) View all
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Article: Nemo regulates cell dynamics and represses the expression of miple, a midkine/pleiotrophin cytokine, during ommatidial rotation.
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ABSTRACT: Ommatidial rotation is one of the most important events for correct patterning of the Drosophila eye. Although several signaling pathways are involved in this process, few genes have been shown to specifically affect it. One of them is nemo (nmo), which encodes a MAP-like protein kinase that regulates the rate of rotation throughout the entire process, and serves as a link between core planar cell polarity (PCP) factors and the E-cadherin-β-catenin complex. To determine more precisely the role of nmo in ommatidial rotation, live-imaging analyses in nmo mutant and wild-type early pupal eye discs were performed. We demonstrate that ommatidial rotation is not a continuous process, and that rotating and non-rotating interommatidial cells are very dynamic. Our in vivo analyses also show that nmo regulates the speed of rotation and is required in cone cells for correct ommatidial rotation, and that these cells as well as interommatidial cells are less dynamic in nmo mutants. Furthermore, microarray analyses of nmo and wild-type larval eye discs led us to identify new genes and signaling pathways related to nmo function during this process. One of them, miple, encodes the Drosophila ortholog of the Midkine/Pleiotrophin secreted cytokines that are involved in cell migration processes. miple is highly up-regulated in nmo mutant discs. Indeed, phenotypic analyses reveal that miple overexpression leads to ommatidial rotation defects. Genetic interaction assays suggest that miple is signaling through Ptp99A, the Drosophila ortholog of the vertebrate Midkine/Pleiotrophin PTPζ receptor.Accordingly, we propose that one of the roles of Nmo during ommatial rotation is to repress miple expression, which may in turn affect the dynamics in E-cadherin-β-catenin complexes.Developmental Biology 02/2013; · 4.07 Impact Factor -
Article: Successful application of preimplantation genetic diagnosis for hypokalaemic periodic paralysis.
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ABSTRACT: Hypokalaemic periodic paralysis is a rare dominant inherited disease where a person suffers sudden falls of circulating potassium concentrations, producing muscle weakness and sometimes severe paralysis. Attacks can occur as frequently as several times a day or once in a year. The age of onset is usually adolescence but symptoms can appear as early as 10 years of age. Muscle weakness can compromise vital functions such as breathing or swallowing and heart arrhythmias are also frequent during attacks. Preimplantation genetic diagnosis, an early form of prenatal diagnosis for couples at risk of transmitting inherited diseases, was used to prevent the transmission of this disease. Six polymorphic short tandem repeat or microsatellite markers (STR) closely linked to the CACNA1S gene were tested. Three fully informative markers were chosen to establish the disease-bearing haplotype in the family and to determine the genetic status of five embryos by multiplex fluorescent heminested PCR. Four of the five embryos tested were diagnosed as non-affected and one as affected. Two embryos were transferred resulting in a singleton pregnancy and the birth of a healthy girl.Reproductive biomedicine online 08/2010; 21(2):206-11. · 2.04 Impact Factor -
Article: Case report: first successful application of preimplantation genetic diagnosis for hereditary angiooedema.
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ABSTRACT: Hereditary angiooedema is an autosomal dominant disease caused by mutations in the SERPING1 gene. It is characterized by oedemas in different parts of the body, being particularly dangerous when swelling involves the upper airway. Preimplantation genetic diagnosis (PGD) was performed in a couple where the woman carries a deletion of 2.9Kb that includes exon 4 of the SERPING1 gene. Four polymorphic short tandem repeat markers were tested in order to establish the disease-bearing haplotype and three of them were fully informative. Amplification efficiency at the preclinical work up ranged from 71% to 100% for each locus and allele drop out rates were between 0% and 20% for the polymorphic markers. The couple underwent PGD using fluorescent multiplex heminested polymerase chain reaction. Six embryos were biopsied and five of them were diagnosed as healthy. Two embryos were transferred and a singleton pregnancy was achieved, resulting in the birth of a healthy boy.Reproductive biomedicine online 06/2010; 21(5):658-62. · 2.04 Impact Factor -
Article: Novel human pathological mutations. Gene symbol: DMD. Disease: muscular dystrophy, Duchenne.
Human Genetics 09/2009; 126(2):338. · 5.07 Impact Factor -
Article: A FRET-based assay for characterization of alternative splicing events using peptide nucleic acid fluorescence in situ hybridization.
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ABSTRACT: We describe a quantitative method for detecting RNA alternative splicing variants that combines in situ hybridization of fluorescently labeled peptide nucleic acid (PNA) probes with confocal microscopy Förster resonance energy transfer (FRET). The use of PNA probes complementary to sequences flanking a given splice junction allows to specifically quantify, within the cell, the RNA isoform generating such splice junction by FRET measure. As a proof of concept we analyzed two alternative splicing events originating from lymphocyte antigen 6 (LY6) complex, locus G5B (LY6G5B) pre-mRNA. These are characterized by the removal of the first intron (Fully Spliced Isoform, FSI) or by retention of such intron (Intron-Retained Isoform, IRI). The use of PNA probe pairs labeled with donor (Cy3) and acceptor (Cy5) fluorophores, suitable to FRET, flanking FSI and IRI specific splice junctions specifically detected both mRNA isoforms in HeLa cells. We have observed that the method works efficiently with probes 5-11 nt apart. The data supports that this FRET-based PNA fluorescence in situ hybridization (FP-FISH) method offers a conceptually new approach for characterizing at the subcellular level not only splice variant isoform structure, location and dynamics but also potentially a wide variety of close range RNA-RNA interactions.Nucleic Acids Research 07/2009; 37(17):e116. · 8.03 Impact Factor
