Open AccessStable transformation of Leptomonas seymouri by circular extrachromosomal elements.
Author(s) -
Vivian Bellofatto,
Jorge Torres-Muñoz,
George Cross
Publication year - 1991
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.88.15.6711
Subject(s) - extrachromosomal dna , biology , plasmid , transformation (genetics) , selectable marker , gene , microbiology and biotechnology , phosphotransferase , vector (molecular biology) , genetics , hygromycin b , origin of replication , recombinant dna
To define the cis-acting sequences necessary for gene expression and DNA replication in trypanosomatids, we have developed a selectable vector that can be grown in Escherichia coli and maintained stably in the insect trypanosomatid Leptomonas seymouri. The vector is relatively small (6 kilobase pairs) and contains a portion of the L. seymouri alpha-tubulin gene positioned in-frame with a truncated neomycin phosphotransferase gene that confers resistance to the aminoglycoside G418. This construct is maintained in cells as a high-copy-number circular extrachromosomal element containing several head-to-tail copies of the transforming plasmid. In L. seymouri, alpha-tubulin-neomycin phosphotransferase fusion RNAs are polyadenylylated and possess a trans-spliced mini-exon. Additional DNA sequences can be inserted into the vector, propagated, and expressed in transformed cells.