title: Multiple forms of chromosome I, II and V in a restricted population of Leishmania infantum contrasting with monomorphism in individual strains suggest haploidy or automixy.
abstract: We have resolved the molecular karyotypes of 22 Leishmania infantum strains isolated between 1980 and 1988 in a restricted geographic area and belonging to zymodemes MON-11, -29 and -33. Three strains were isolated from sandflies and all the others from human cutaneous lesions. A high degree of karyotypic homology is observed among these strains, contrasting with the highly polymorphic MON-1 strains isolated in the same area. We have analysed the time-dependent evolution of size variants of chromosomes I to V, each identified by chromosome-specific DNA probes. More evidence is given for the role of subtelomeric regions in chromosomal size variation in Leishmania for both chromosomes I and II. At the population level, the chromosomes I, II and V are present in respectively 8, 4 and 3 distinct sizes. Furthermore, and despite the small size of the sample, various combinations were observed among these different chromosomal forms. These results could be explained by the occurrence of a high rate of recurrent mutations or of genetic exchange. In contrast, only one chromosomal form was observed in individual karyotypes for the chromosomes I-V. These results could tally with the hypothesis of a haploid organisation for these chromosomes and strains, or, in the frame of a diploid organisation, with the hypothesis of a predominantly automictic sexuality giving rise to 2 identical forms of the homologues in the same strain.
authors.affiliation: Laboratoire d'Ecologie Médicale et Pathologie Parasitaire, CNRS, Faculté de Médecine, Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Blaineau
authors.forename: P
authors.initials: P
authors.lastname: Bastien
authors.forename: M
authors.initials: M
authors.lastname: Pagès
mesh_terms: D000818:Animals; D002875:Chromosomes; D015342:DNA Probes; D004262:DNA Restriction Enzymes; D016054:DNA, Protozoan / Q000235:genetics; D005602:France; D014644:Genetic Variation; D006238:Haploidy; D007621:Karyotyping; D007893:Leishmania donovani / Q000235:genetics*; D013030:Spain
chemical_list: D015342:DNA Probes; D016054:DNA, Protozoan; D004262:DNA Restriction Enzymes