Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1991 Apr;10(4):1009-16.
doi: 10.1002/j.1460-2075.1991.tb08035.x.

Direct and inverted DNA repeats associated with P-glycoprotein gene amplification in drug resistant Leishmania

M Ouellette  1 , E Hettema, D Wüst, F Fase-Fowler, P Borst
Affiliations

Direct and inverted DNA repeats associated with P-glycoprotein gene amplification in drug resistant Leishmania

M Ouellette et al. EMBO J. 1991 Apr.

Abstract

The H circle of Leishmania species contains a 30 kb inverted duplication separated by two unique DNA segments, a and b. The corresponding H region of chromosomal DNA has only one copy of the duplicated DNA. We show here that the chromosomal segments a and b are flanked by inverted repeats (198 and 1241 bp) and we discuss how these repeats could lead to formation of H circles from chromosomal DNA. Selection of Leishmania tarentolae for methotrexate resistance indeed resulted in the de novo formation of circles with long inverted duplication, but two mutants selected for arsenite resistance contained new H region plasmids without such duplications. One of these plasmids appears due to a homologous recombination between two P-glycoprotein genes with a high degree of sequence homology. Our results show how the same DNA region in Leishmania may be amplified to give plasmids with or without long inverted duplications and apparently by different mechanisms.

PubMed Disclaimer

References

    1. Anal Biochem. 1984 Feb;137(1):266-7 - PubMed
    1. Nucleic Acids Res. 1984 Jan 11;12(1 Pt 1):387-95 - PubMed
    1. Mol Cell Biol. 1983 Apr;3(4):699-711 - PubMed
    1. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463-7 - PubMed
    1. J Mol Biol. 1967 Jun 14;26(2):365-9 - PubMed

Publication types