Interclonal variations in molecular karyotype in Leishmania infantum imply a 'mosaic' strain structure.
The molecular karyotypes of 36 clones derived from 8 strains of Leishmania infantum were examined by pulsed-field gel electrophoresis. Although there appeared to be a high degree of genetic relatedness between the clones and the parent strain, a limited degree of polymorphism was noted in 50% of the clones, expressed mainly as the presence of an additional chromosome or as a chromosome size modification. Repeated subcloning in one strain showed that chromosomal rearrangements could occur during the cloning process. Chromosome homologies were examined by Southern analysis with chromosome-specific DNA probes. The results suggest a disomy for some chromosomes, but cannot exclude aneuploidy. The mechanisms possibly leading to such heterogeneity are discussed: they could involve frequent DNA amplification/deletion, and imply a 'mosaic' structure of the cultured strains or clones, with different individuals possessing differently sized versions of the same chromosomes.
Bastien
P
P
Laboratoire d'Ecologie Médicale et Pathologie Parasitaire, UA 691 CNRS, Faculté de Médecine, Montpellier, France.
Blaineau
C
C
Taminh
M
M
Rioux
J A
JA
Roizès
G
G
Pagès
M
M
D000818:Animals; D015139:Blotting, Southern; D002999:Clone Cells; D007621:Karyotyping; D007893:Leishmania donovani / Q000235:genetics*; D009030:Mosaicism; D012150:Polymorphism, Restriction Fragment Length; D012689:Sequence Homology, Nucleic Acid