title: Multilocus sequence and microsatellite identification of intra-specific hybrids and ancestor-like donors among natural Ethiopian isolates of Leishmania donovani.
abstract: Protozoan parasites of the genus Leishmania (Kinetoplastida: Trypanosomatidae) cause widespread and devastating human diseases. Visceral leishmaniasis is endemic in Ethiopia where it has also been responsible for fatal epidemics. It is postulated that genetic exchange in Leishmania has implications for heterosis (hybrid vigour), spread of virulent strains, resistance to chemotherapeutics, and exploitation of different hosts and vectors. Here we analyse 11 natural Ethiopian Leishmania donovani isolates consisting of four putative hybrids, seven parent-like isolates and over 90 derived biological clones. We apply a novel combination of high resolution multilocus microsatellite typing (five loci) and multilocus sequence typing (four loci) that together distinguish parent-like and hybrid L. donovani strains. Results indicate that the four isolates (and their associated biological clones) are genetic hybrids, not the results of mixed infections, each possessing heterozygous markers consistent with inheritance of divergent alleles from genetically distinct Ethiopian L. donovani lineages. The allelic profiles of the putative hybrids may have arisen from a single hybridisation event followed by inbreeding or gene conversion, or alternatively from two or more hybridisation events. Mitochondrial sequencing showed uniparental maxicircle inheritance for all of the hybrids, each possessing a single mitochondrial genotype. Fluorescence activated cell sorting analysis of DNA content demonstrated that all hybrids and their associated clones were diploid. Together the data imply that intra-specific genetic exchange is a recurrent feature of natural L. donovani populations, with substantial implications for the phyloepidemiology of Leishmania.
authors.affiliation: Serology Diagnostics and Research Laboratory, Centers for Disease Control and Prevention, Division of Vector-Borne Diseases Dengue Branch, San Juan, PR, United States; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Gelanew
authors.affiliation: Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Asrat
authors.initials: A
authors.lastname: Hailu
authors.affiliation: Institute of Microbiology and Hygiene, Charité University Medicine, Berlin, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schőnian
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Lewis
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Miles
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. Electronic address: Matthew.yeo@lshtm.ac.uk.
authors.forename: Matthew
authors.initials: M
authors.lastname: Yeo
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial; D005002:Ethiopia / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007893:Leishmania donovani / Q000235:genetics*; D007898:Leishmaniasis, Visceral / Q000453:epidemiology / Q000469:parasitology*; D018895:Microsatellite Repeats / Q000235:genetics*; D058885:Multilocus Sequence Typing
chemical_list: D004272:DNA, Mitochondrial
keywords: Genetic exchange; Hybridisation; Leishmania; MLMT; MLST; Recombination