Formation of extrachromosomal circular amplicons with direct or inverted duplications in drug-resistant Leishmania tarentolae
نویسندگان
چکیده
منابع مشابه
Formation of Linear Amplicons with Inverted Duplications in Leishmania Requires the MRE11 Nuclease
Extrachromosomal DNA amplification is frequent in the protozoan parasite Leishmania selected for drug resistance. The extrachromosomal amplified DNA is either circular or linear, and is formed at the level of direct or inverted homologous repeated sequences that abound in the Leishmania genome. The RAD51 recombinase plays an important role in circular amplicons formation, but the mechanism by w...
متن کاملFormation of linear inverted repeat amplicons following targeting of an essential gene in Leishmania
Attempts to inactivate an essential gene in the protozoan parasite Leishmania have often led to the generation of extra copies of the wild-type alleles of the gene. In experiments with Leishmania tarentolae set up to disrupt the gene encoding the J-binding protein 1 (JBP1), a protein binding to the unusual base beta-D-glucosyl-hydroxymethyluracil (J) of Leishmania, we obtained JBP1 mutants cont...
متن کاملCo-existence of circular and multiple linear amplicons in methotrexate-resistant Leishmania.
Circular and linear amplicons were analyzed in detail in Leishmania tropica cells resistant to methotrexate (MTX). Both types of elements presented sequences related to the H locus and coexisted in resistant cells. The linear amplicons appeared first during the selection process (at 10 microM MTX) and varied with regard to size and structure in cells exposed to increasing concentrations of drug...
متن کاملHomologous recombination between direct repeat sequences yields P-glycoprotein containing amplicons in arsenite resistant Leishmania.
The protozoan parasite Leishmania often responds to drug pressure by amplifying part of its genome. At least two loci derived from the same 800 kb chromosome were amplified either as extrachromosomal circles or linear fragments after sodium arsenite selection. A 50 kb linear amplicon was detected in six independent arsenite mutants and revertants grown in absence of arsenite rapidly lost the am...
متن کاملParental origin and mechanisms of formation of cytogenetically recognisable de novo direct and inverted duplications.
Cytogenetic, FISH, and molecular results of 20 cases with de novo tandem duplications of 18 different autosomal chromosome segments are reported. There were 12 cases with direct duplications, three cases with inverted duplications, and five in whom determination of direction was not possible. In seven cases a rearrangement between non-sister chromatids (N-SCR) was found, whereas in the remainin...
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ژورنال
عنوان ژورنال: Molecular and Cellular Biology
سال: 1996
ISSN: 0270-7306,1098-5549
DOI: 10.1128/mcb.16.7.3587