This work describes the development and functional testing of two episomes for stable transfection of
Trypanosoma cruzi
. pHygD contained the 5'- and 3'- flanking regions of the gene encoding the cathepsin B-like protease of
T. cruzi as functional trans-splicing and polyadenylation signals for the hyg
R ORF. Evidence is presented to support extrachromosomal maintenance and organization as tandem repeats in transfected parasites. pPac was derived from pHygD by replacement of the entire hyg
R ORF with a pur
R coding region. The ability to modify pHygD and the availability of the complete DNA sequence make these plasmids useful tools for the genetic manipulation of
T. cruzi.
