Tetracycline-controlled gene expression in Entamoeba histolytica.
To provide further tools for functional genetics of the protozoan parasite Entamoeba histolytica, we have tested the suitability of the bacterial TN10-encoded tet-repressor/tet-operator system for gene regulation in ameba trophozoites. Expression of the tet-repressor within the ameba was driven by the wild-type endogenous lectin gene promoter from episomal transfected plasmids. Tetracycline-inducible expression of a reporter gene driven by a modified tet-operator-bearing lectin gene promotor was monitored by transient and episomal transfection. Promotor activity was dependent on the position of the tet-operator insertion. Under appropriate conditions, expression of the reporter gene in tet-repressor expressing cells revealed only background levels but was inducible up to 240-fold by the addition of non-toxic amounts of tetracycline reaching full activity within 36 to 48 h. Because of the tight and rapid control by tetracycline, the tet-repressor controlled lectin gene promotor should be a usefull tool for reverse genetic approaches in E. histolytica as well as for recombinant protein expression within this anaerobic organism.
Hamann
L
L
Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Buss
H
H
Tannich
E
E
D000818:Animals; D004748:Entamoeba histolytica / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D017125:Genes, Protozoan / Q000235:genetics*; D017930:Genes, Reporter; D005822:Genetic Vectors; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D013752:Tetracycline
D012097:Repressor Proteins; C034811:tetracycline resistance-encoding transposon repressor protein; D013752:Tetracycline