Evidence of genetic recombination in Leishmania.
In the genus Leishmania there has been no convincing demonstration of genetic exchange, and it has been proposed that reproduction is clonal. However, preliminary characterization of two strains of Leishmania isolated from wild animals in a zoonotic focus of cutaneous leishmaniasis in the Eastern Province of Saudi Arabia, has suggested that they may represent hybrids of Leishmania major and Leishmania arabica. Evidence presented here strongly supports this hypothesis. Isoenzyme analysis and molecular karyotyping of cloned organisms indicated that the putative hybrids are distinct from other species of Leishmania, and possess characteristics of both L. major and L. arabica. Experiments using highly specific probes demonstrated that kinetoplast minicircle DNA from the putative hybrid contained L. major-specific, but not L. arabica-specific sequences. DNA fingerprinting data obtained using 6 genomic DNA probes were consistent in all cases with a L. major/L. arabica recombinant genotype, and implied both diploidy and allelic segregation. These observations suggest that sexual reproduction may generate genetic diversity within natural Leishmania populations.
Kelly
J M
JM
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, U.K.
Law
J M
JM
Chapman
C J
CJ
Van Eys
G J
GJ
Evans
D A
DA
D000818:Animals; D016172:DNA Fingerprinting; D015342:DNA Probes; D004270:DNA, Circular / Q000235:genetics; D018105:DNA, Kinetoplast; D016054:DNA, Protozoan / Q000235:genetics*; D004171:Diploidy; D015151:Immunoblotting; D007891:Leishmania / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D007895:Leishmania tropica / Q000235:genetics* / Q000276:immunology; D009693:Nucleic Acid Hybridization; D011995:Recombination, Genetic; D012098:Reproduction; D012529:Saudi Arabia
D015342:DNA Probes; D004270:DNA, Circular; D018105:DNA, Kinetoplast; D016054:DNA, Protozoan