Cross-species genetic exchange between visceral and cutaneous strains of Leishmania in the sand fly vector.
Genetic exchange between Leishmania major strains during their development in the sand fly vector has been experimentally shown. To investigate the possibility of genetic exchange between different Leishmania species, a cutaneous strain of L. major and a visceral strain of Leishmania infantum, each bearing a different drug-resistant marker, were used to coinfect Lutzomyia longipalpis sand flies. Eleven double-drug-resistant progeny clones, each the product of an independent mating event, were generated and submitted to genotype and phenotype analyses. The analysis of multiple allelic markers across the genome suggested that each progeny clone inherited at least one full set of chromosomes from each parent, with loss of heterozygosity at some loci, and uniparental retention of maxicircle kinetoplast DNA. Hybrids with DNA contents of approximately 2n, 3n, and 4n were observed. In vivo studies revealed clear differences in the ability of the hybrids to produce pathology in the skin or to disseminate to and grow in the viscera, suggesting polymorphisms and differential inheritance of the gene(s) controlling these traits. The studies, to our knowledge, represent the first experimental confirmation of cross-species mating in Leishmania, opening the way toward genetic linkage analysis of important traits and providing strong evidence that genetic exchange is responsible for the generation of the mixed-species genotypes observed in natural populations.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Audrey
A
Romano
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Ehud
E
Inbar
Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892; and.
Alain
A
Debrabant
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Melanie
M
Charmoy
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Phillip
P
Lawyer
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Flavia
F
Ribeiro-Gomes
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Mourad
M
Barhoumi
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Michael
M
Grigg
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.
Jahangheer
J
Shaik
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.
Deborah
D
Dobson
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.
Stephen M
SM
Beverley
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; dsacks@nih.gov.
David L
DL
Sacks
D000818:Animals; D007303:Insect Vectors / Q000235:genetics*; D007891:Leishmania / Q000145:classification / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D020641:Polymorphism, Single Nucleotide; D011576:Psychodidae / Q000469:parasitology*; D013045:Species Specificity
Leishmania; genetic exchange; sand fly