. "0"^^ . . "Plant transgenes often display variable, often unpredictable expression caused by epigenetic modifications of transgenic DNA (T-DNA). Transgene instability can potentially hamper application of transgenic technology in agriculture and biotechnology. Therefore this project focuses on the analysis of epigenetic stability of plant transgenes. Association between epigenetic modification of cytosine residues in DNA and gene silencing has been described in both mammals and plants. We propose to carry out a detailed investigation of our initial observation of methylation spreading in posttranscriptionally silenced transgenic loci of Nicotiana tabacum that occured in cell culture. Several novel epiallalelic variants of the transgene silencer locus will be analysed for gene expression of the reporter gene, type of silencing and in trans silencing capacities. Evolutionary consequences of spreading phenomenon will be assessed by following mitotic and meiotic transmission of different methylation features."@en . "In the nucleus, transgene loci may interact with each other and as well as with endogenous genes of a host organism. As a result of these interactions there is a hardly predictable expression of genetic traits critical for application of transgene techno"@en . . . . . . "11"^^ . "Je zn\u00E1mo, \u017Ee transgenn\u00ED lokusy mohou v bun\u011B\u010Dn\u00E9m j\u00E1d\u0159e interagovat jak mezi sebou tak i s geny hostitelsk\u00E9ho organismu. N\u00E1\u0161 v\u00FDzkum zalo\u017Een\u00FD na kombinaci klasick\u00E9ho Mendelova k\u0159\u00ED\u017Een\u00ED rostlin a modern\u00EDch metod molekul\u00E1rn\u00ED biologie p\u0159inesl poznatek, \u017Ee pouze"@cs . "11"^^ . . . "Epigenetic regulation of gene expression in transgenic and endogenous loci of higher plants"@en . . "GA521/04/0775" . . . "http://www.isvav.cz/projectDetail.do?rowId=GA521/04/0775"^^ . "Neuvedeno."@en . . . . "0"^^ . "Rostlinn\u00E9 transgeny \u010Dasto oproti teoretick\u00FDm p\u0159edpoklad\u016Fm vykazuj\u00ED sn\u00ED\u017Eenou expresi v d\u016Fsledku epigenetick\u00FDch modifikac\u00ED (nap\u0159\u00EDklad metylace DNA), co\u017E negativn\u011B ovliv\u0148uje aplikaci geneticky modifikovan\u00FDch rostlin v zem\u011Bd\u011Blstv\u00ED a biotechnologi\u00EDch. Asociace mezi metyla\u010Dn\u00ED modifikac\u00ED DNA a uml\u010Dov\u00E1n\u00EDm genov\u00E9 exprese byla ov\u011B\u0159en\u00E1 na mnoha \u017Eivo\u010Di\u0161n\u00FDch i rostlinn\u00FDch modelech. V p\u0159edkl\u00E1dan\u00E9m projektu navrhujeme prov\u00E9st hlub\u0161\u00ED anal\u00FDzu na\u0161eho p\u016Fvodn\u00EDho pozorov\u00E1n\u00ED - \u0161\u00ED\u0159en\u00ED metylace DNA v posttranskrip\u010Dn\u011B uml\u010Den\u00E9m transgenn\u00EDm lokusu Nicotiana tabacum v pr\u016Fb\u011Bhu kulivace bun\u011Bk in vitro. Na modelov\u00FDch transgenn\u00EDch lini\u00EDch budou zkoum\u00E1ny v\u00FDvojov\u00E9, genetick\u00E9 a evolu\u010Dn\u00ED aspekty tohoto fenom\u00E9nu. Bude sledov\u00E1n vliv epigenetick\u00FDch modifikac\u00ED na expresi reporterov\u00E9ho genu pro bakteri\u00E1ln\u00ED neomycinfosfotransfer\u00E1zu. Linie obsahuj\u00EDc\u00ED epimutovan\u00E9 alely transgenu budou d\u00E1le podrobeny anal\u00FDze z hlediska schopnosti induktoru uml\u010Dovat expresi homologn\u00EDho lokusu in trans. Budou hled\u00E1ny paralely v epigenetick\u00E9m" . . . . . "1"^^ . "Epigenetick\u00E1 regulace genov\u00E9 exprese v transgenn\u00EDch a endogenn\u00EDch lokusech vy\u0161\u0161\u00EDch rostlin" . "2007-10-16+02:00"^^ . . .