Analyse d'un élément régulateur positif et mise en évidence d'un promoteur alternatif dans le premier intron du gène de l'alpha-foetoprotéine

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Analyse d'un élément régulateur positif et mise en évidence d'un promoteur alternatif dans le premier intron du gène de l'alpha-foetoprotéine

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Identification of an enhancer and an alternative promoter in the first intron of the alpha-fetoprotein gene

In this study we have characterized a positive regulatory region located in the first intron of the alpha-fetoprotein (AFP) gene. We show that the enhancer activity of the region depends on a 44 bp sequence centered on a CACCC motif. The sequence is the target of the two zinc fingers transcription factors BKLF and YY1. The introduction of a mutation destroying the CACCC box impairs the binding of BKLF but improves that of YY1. Moreover, the mutated sequence behaves as a negative control element, suggesting that BKLF behaves as a positive factor and that YY1 is a negative one. We also demonstrate the existence of a novel, tissue-specific AFP mRNA isoform present in the yolk sac and fetal liver which initiates from an alternative promoter located approximately 100 bp downstream of the enhancer element. The transcriptional start site controlled by this new promoter (called P2), was mapped to 66 bp downstream of a TATA box. A putative AUG translation site in-frame with exon 2 of the classical gene was found 295 bp downstream of the transcription start site. Like the traditional AFP promoter (P1), the P2 promoter is active in the yolk sac and fetal liver. Embryonic stem cells with an AFP knock-in gene containing either the P2 promoter or deleted for it were isolated and comparative analysis of embryonic bodies derived from these cells suggests that the P2 promoter contributes to early expression of the AFP gene.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Assignment of Sp genes to rat chromosome bands 7q36 (Sp1), 10q31→q32.1 (Sp2), 3q24→q31 (Sp3) and 6q33 (Sp4) and of the SP2 gene to human chromosome bands 17q21.3→q22 by in situ hybridization

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Physiological role of the putative ammonium transporter RhCG in the mouse

Ammonium excretion into urine is a major process essential to the regulation of acid-base homeostasis. We have shown that Rh-type proteins, including renal RhCG, belong to the Mep/Amt family of ammonium transporters and promote bi-directional ammonium transport upon heterologous expression in yeast. To study the physiological role of RhCG and to test a potential function in ammonium excretion, we have generated mice bearing an invalidation of the corresponding gene. © 2006 Elsevier SAS. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Predictive Molecular Markers: A New Window of Opportunity in the Adjuvant Setting

Part II, section 2info:eu-repo/semantics/publishe

Localization of 54 rats genes, and definition of new synteny groups conserved in the human and the rat

In order to improve the rat gene map and comparative mapping with the human and the mouse, we determined the chromosome localization of 54 rat genes. Most genes encode transcription factors or other regulatory proteins of cancer relevance. The human homologs of four genes were also assigned to their respective chromosome. These data generated anchor points between the recently established radiation hybrid maps and the genetic and cytogenetic maps. They improve comparative mapping between the rat, the mouse, and the human gene maps, and in particular they disclose four new synteny groups conserved in the rat and the human. These new localizations should also be useful for the identification of genes involved in the control of quantitative traits such as cancer susceptibility or diabetes.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

RGM medium versus MGIT™ for isolation of nontuberculous mycobacteria from sputum of patients with cystic fibrosis.

Background: Isolation of non-tuberculous mycobacteria (NTM) from sputum of patients with cystic fibrosis (CF) is challenging as, due to contaminant overgrowth, many cultures need to be abandoned. RGM medium is a novel agar-based culture medium which contains growth factors and selective agents to allow isolation of NTM. Material and methods: In this prospective study, all patients of the clinic on regular follow-up and without lung transplant (n = 188, 18y + :57%) were eligible if able to expectorate at least 2 ml either spontaneously or at the end of a full session of physiotherapy during a routine visit. The samples were inoculated onto both RGM medium and MGIT, the latter having been preceded by a decontamination step using NALC (0.5%)-NaOH (4%). Both media were incubated for 42 days. Identification of NTM was confirmed by MALDI TOF MS and rpoB sequencing. Results: Out of 123 eligible patients, data are currently available for 106 (M: 57; PS: 17; mean age: 27.1 y ± 12.6, range: 6.8–69; mean FEV1: 79% pr ± 23; chronic colonization by P. aeruginosa: 31%). Potentially pathogenic NTM were recovered from 9 patients. Concordant positive results were obtained in only 3 patients, all with M abscessus (MABSC). RGM and MGIT enabled the isolation of 7 and 5 NTM strains respectively, with 2 undetected NTM for RGM (MABSC:2) and 4 for MGIT (M chelonae:2, M avium:1, M kansasii:1). Whereas 40 MGIT (34.5%) were contaminated and had to be discontinued, 11 RGM (9.5%) were contaminated (p < 0.001) and remained interpretable due to weak contaminant overgrowth. In addition, contaminants isolated with RGM all were relevant pathogens in CF (A. xylosoxidans:7, B. gladioli:1, B. multivorans:1, yeast:2). Conclusion: Whether RGM cultures are as sensitive as MGIT to isolate relevant NTM remains to be investigated. However, RGM cultures are far less contaminated, easier to perform and cheaper than liquid media. These characteristics make them an attractive tool allowing for more regular NTM screening