A robust inducible-repressible promoter greatly facilitates gene knockouts, conditional expression, and overexpression of homologous and heterologous genes in Tetrahymena thermophila.

ABSTRACT: The Cd(2+)-inducible metallothionein (MTT1) gene was cloned from Tetrahymena thermophila. Northern blot analysis showed that MTT1 mRNA is not detectable in the absence of Cd(2+), is induced within 10 min of its addition, is expressed in proportion to its concentration, and rapidly disappears upon its withdrawal. Similarly, when the neo1 gene coding region flanked by the MTT1 gene noncoding sequences was used to disrupt the MTT1 locus, no transformants were observed in the absence of Cd(2+), and the number of transformants was proportional to increased Cd(2+) concentration. The neo3 cassette, in which the MTT1 promoter replaced the histone gene HHF1 promoter of the previously used neo2 cassette, transformed cells at much higher frequencies than neo2 and produced germ-line knockouts where ne

SUBMITTER: Shang Y 

PROVIDER: S-EPMC122593 | biostudies-literature | 2002 Mar

REPOSITORIES: biostudies-literature