title: First report of genetic hybrids between two very divergent Leishmania species: Leishmania infantum and Leishmania major.
abstract: The genus Leishmania includes many pathogenic species which are genetically very distant. The possibility of genetic exchange between different strains is still an important and debated question. Very few genetic hybrids (i.e., offspring of genetically dissimilar species) have been described in Leishmania. In this study, we report the first example of genetic hybrids occurring between two divergent Leishmania species, Leishmania infantum and Leishmania major. These two species have distinct geographical distributions and are transmitted by different vector species to different mammalian reservoir hosts. These hybrid strains were isolated in Portugal from immunocompromised patients and characterized by molecular and isoenzymatic techniques. These approaches showed that these chimeric strains probably contained the complete genome of both L. major and L. infantum. We believe this is the first report of genetic hybrids between such phylogenetically and epidemiologically distant species of Leishmania. This raises questions about the frequency of such cross-species genetic exchange in natural conditions, modalities of hybrid transmission, their long term maintenance as well as the consequences of these transfers on phenotypes such as drug resistance or pathogenicity.
authors.affiliation: Laboratoire de Parasitologie, Centre National de Référence des Leishmania, 163 rue Broussonet, F34090 Montpellier, France. christophe.ravel@univ-montp1.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Ravel
authors.forename: Sofia
authors.initials: S
authors.lastname: Cortes
authors.forename: Francine
authors.initials: F
authors.lastname: Pratlong
authors.forename: Florent
authors.initials: F
authors.lastname: Morio
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Dedet
authors.forename: Lenea
authors.initials: L
authors.lastname: Campino
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000469:parasitology; D000328:Adult; D000818:Animals; D001483:Base Sequence; D016054:DNA, Protozoan / Q000235:genetics; D004592:Electrophoresis, Starch Gel; D005260:Female; D006801:Humans; D006824:Hybridization, Genetic; D007527:Isoenzymes; D018314:Leishmania infantum / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D018320:Leishmania major / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: D016054:DNA, Protozoan; D007527:Isoenzymes