ISSN:
1573-5028
Keywords:
expression system
;
Physcomitrella patens
;
regulated promoter
;
switchable promoter
;
tetracycline
;
Top 10 promoter
;
transgenic plants
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract As ancestors of higher plants, mosses offer advantages as simple model organisms in studying complex processes such as development and signal transduction. Overexpression of transgenes after genetic transformation is a powerful technique in such studies. To establish a controllable expression system for this experimental approach we expressed a chimeric protein consisting of the Tn10-encoded Tet repressor and the activation domain of Herpes simplex virion protein 16 in the moss Physcomitrella patens. We showed that this protein activates transcription from a suitable target promoter (Top 10) containing seven operators upstream of a TATA box. In media containing very low levels of tetracycline (1 mg/l), expression levels of a β-glucuronidase (GUS) reporter gene dropped to 〈1% of that in the absence of tetracycline. This regulation is due to interference of tetracycline with the DNA binding activity of the Tet repressor portion of the chimeric transcriptional activator. Stable transformants grown for three weeks on tetracycline-containing media showed negligible GUS activity, whereas GUS was expressed strongly within 24 h of transfer to tetracycline-free media. Potent and stringently regulated expression of other, physiologically active genes is thus readily available in the moss system using the convenient Top 10 expression system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00017815
Permalink
