Effect of large targeted deletions on the mitotic stability of an extra chromosome mediating drug resistance in Leishmania

被引:19
作者
Dubessay, P
Ravel, C
Bastien, P
Lignon, MF
Ullman, B
Pagès, M
Blaineau, C
机构
[1] Fac Med, Lab Parasitol Mycol, CNRS UMR5093 Genome & Biol Mol Protozoaires Paras, F-34090 Montpellier, France
[2] Oregon Hlth Sci Univ, Dept Biochem & Mol Biol, Portland, OR 97201 USA
关键词
D O I
10.1093/nar/29.15.3231
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A mitotically stable linear extra chromosome obtained in a Leishmania donovani strain rendered mycophenolic acid-resistant has been physically mapped. This 290-kb chromosome has an inverted duplicated structure around a central inversion region, and is derived from a conservative amplification event of a similar to 140-kb subtelomeric end of chromosome 19. Large-sized targeted deletions of the central region were performed through homologous recombination using three specific transfection vectors. The size of the extra chromosome was thus successfully reduced from 290 to 260, 200 and 120 kb respectively. The mitotic stability of these chromosomes was then analysed in drug-free cultures over > 140 days. Results differed according to the deletion created. By contrast with the smallest deletion the two largest deletions altered mitotic stability, leading to progressive loss of the size-reduced chromosomes with similar kinetics in both mutants. The 30-kb region common to both deletions may therefore be considered as involved in mitotic stability. A 44-kb contig covering this region could be assembled and sequenced. The analysis of this sequence did not reveal any sequence elements typical of centromeric DNA. By contrast, its enrichment in homopolymer tracts suggests that this region might contain an origin of replication.
引用
收藏
页码:3231 / 3240
页数:10
相关论文
共 61 条
[61]   A RIBOSOMAL-RNA GENE PROMOTER AT THE TELOMERE OF A MINICHROMOSOME IN TRYPANOSOMA-BRUCEI [J].
ZOMERDIJK, JCBM ;
KIEFT, R ;
BORST, P .
NUCLEIC ACIDS RESEARCH, 1992, 20 (11) :2725-2734