1,721,154 research outputs found
Evidence for a host role in regulating the activity of transposable elements in Drosophila melanogaster: the case of the persistent instability of Bari 1 elements in Charolles stock
No full textIn most reports in which the activity of numerous Drosophila transposon families has been studied, only a subset of the families tested appears mobile. A comparison of these data shows that there are no transposons inherently more unstable than others and suggests that host factors regulate the activity of transposable elements. Consistent with this conclusion are the properties of Bari 1 elements, which are the only ones of the 14 families tested to be unstable in Charolles stock. Instability is persistent over 53 generations and appears to affect recurrent insertion sites
Cyclin DI gene contains a cryptic promoter that is functional in human cancer cells
No full textA novel cyclin D1 (CCND1)-TROP2 fusion oncogene has been isolated from human cancer cells. Unexpectedly, the chimeric cDNA was found to express TROP2 in the absence of exogenous promoters. Mutagenesis of the TROP2 and CCND1 sequences and in vitro transcription/translation show that a cryptic promoter is present in the 3 ' coding region of CCND1. The CCND1 cryptic promoter is functional in luciferase assays, where it augments the basal expression levels by eightfold and efficiently cooperates with an SV-40 enhancer. The transcription start sites of the cryptic promoter map at bases 797 and 935 of CCND1, as determined by RNase protection assays. The cryptic promoter possesses canonical binding sites for ubiquitous transcription factors and W/S, XI, and CAAT/Y boxes that are characteristic of major histocompatibility complex class II gene promoters. Remarkably, the cryptic CCND1 promoter is active in human cancer cells and generates a truncated transcript that contains CCND1 instability sequences. Thus, this novel CCND1 transcription unit may play a role in the regulation of the expression of cyclin D1 and in tumor cell growth, (C) 2001 Wiley-Liss, Inc
Intragenomic distribution and stability of transposable elements in euchromatin and heterochromatin of Drosophila melanogaster: Elements with inverted repeats Bari 1, hobo, and pogo
No full textThe elements of the Bari 1, hobo, and pogo transposon families that are located in euchromatin, heterochromatin, and on the Y chromosome have been identified, and their stability has been assessed by Southern blot analysis. The fraction of heterochromatic elements appears to be distinctive of all transposon families tested, except for Bari 1. Evidence for instability of heterochromatic elements is described. The analysis of unstable elements in different Drosophila stocks suggests that the host genome contributes to the stability/instability of transposon families
Is there a correlation between mobility of transposable elements and their accumulation in heterochromatin of Drosophila melanogaster ?
No full textIntragenomic distribution and stability of transposable elements in euchromatin and heterochromatin of Drosophila melanogaster: Non-LTR retrotransposon
No full textThe intragenomic location of the elements of the I, G, jockey, F, and Doc transposon families has been studied by the Southern blot analysis, in 12 laboratory Drosophila melanogaster stocks. Elements located in euchromatin, heterochromatin, and on the Y chromosome are identified, and their stability has been assessed by comparing the autoradiographs detected in different stocks and analysis of individual flies, Evidence is shown suggesting that preferential location in euchromatin or heterochromatin and the distribution within heterochromatin are distinctive of transposon families. Elements located in heterochromatin can be unstable. These results are discussed in the context of the relationship between transposable elements and the host genome
Intragenomic distribution and stability of transposable elements in euchromatin and heterochromatin of Drosophila melanogaster : non-LTR retrotransposons.
No full textIntragenomic distribution and stability of transposable elements in euchromatin and heterochromatin of Drosophila melanogaster: elements with inverted repeats Bari, hobo and pogo.
No full textEvidence for a role of the host in regulating the activity of transposable elements in D. melanogaster
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