Transgene silencing of invertedly repeated transgenes is released upon deletion of one of the transgenes involved.
Plant Mol Biol
; 46(4): 433-45, 2001 Jul.
Article
en En
| MEDLINE
| ID: mdl-11485200
To analyse experimentally the correlation between transgene silencing and the presence of an inverted repeat in transgenic Arabidopsis thaliana plants, expression of the beta-glucuronidase (gus) gene was studied when present as a convergently transcribed inverted repeat or as a single copy in otherwise isogenic lines. In transformants containing two invertedly repeated gus genes separated by a 732 bp palindromic sequence, gus expression was low, as exemplified by the expression levels in the parental line KH15. The parental KH15 locus could induce efficiently in trans silencing of gus copies at allelic and non-allelic positions. In transformants containing two invertedly repeated gus genes separated by a 826 bp non-repetitive spacer region, gus expression was high or intermediate, especially in hemizygous state and at late developmental stages, as demonstrated in detail for line KHsb67. Removal of one of the gus copies by Cre recombinase resulted in all cases in constitutively high gus expression in hemizygous as well as in homozygous state. The derived deletion lines could no longer induce in trans silencing of homologous gus copies. The results show that convergent transcription of transgenes in an inverted repeat is an important parameter to trigger their silencing and that co-transformation of two T-DNAs with identical transgenes can be used to obtain inverted repeats and targeted co-suppression of the homologous endogenes. Moreover, the data suggest that the spacer region in between the inverted genes plays a role in the efficiency of initiating and maintaining silencing.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Secuencias Repetitivas de Ácidos Nucleicos
/
Eliminación de Gen
/
Transgenes
/
Silenciador del Gen
Idioma:
En
Revista:
Plant Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Bélgica
Pais de publicación:
Países Bajos