THE GP63 GENE LOCUS, A TARGET FOR GENETIC-CHARACTERIZATION OF LEISHMANIA BELONGING TO SUBGENUS VIANNIA

In present study the gp63 gene locus was used as a target for genetic characterization of Leishmania parasites by 2 methods: (i) RFLP analys is with several restriction enzymes (gp63-RFLP), and (ii) intra-genic PCR amplification coupled with restriction analysis (PCR-RFLP). Both m ethods were applied to a large number of natural isolates belonging to 4 species of the subgenus Viannia, namely L. (V.) braziliensis, L. (V .) peruviana, L. (V.) guyanensis and L. (V.) lainsoni: reference stock s of subgenus Leishmania were included as outgroups. Multilocus isoenz yme typing (MLEE) was used as a reference. On the one hand gp63-RFLP e videnced an extensive polymorphism and revealed specific markers for s ubgenus, species and geographical populations: congruence with MLEE wa s demonstrated statistically. The particular interest of gp63-RFLP was illustrated by infra-specific polymorphism, because of the possible r elationship with phenotype diversity. On the other hand intra-genic am plification was less resolutive than gp63-RFLP, but also allowed discr imination of the 2 subgenera (PCR alone) and all the species tested in the subgenus Viannia (PCR-RFLP). PCR-RFLP presents an important opera tional advantage as it allows genetic characterization of minute amoun ts of parasites, using Leishmania specific primers. The polymorphism r evealed by gp63-RFLP and PCR-RFLP illustrates the very high genomic an d genetic plasticity of gp63 genes.