THE RFLP ANALYSIS OF THE BETA-TUBULIN GENE REGION IN NEW-WORLD LEISHMANIA

We have examined the similarities and differences in the organization of tubulin genes in New World Leishmania by restriction endonuclease d igestion of genomic DNA and Southern blot analysis, using heterologous and homologous tubulin gene probes. as judged by the hybridization pa ttern and the restriction fragment length polymorphism (RFLP), there w ere large differences in both the restriction and hybridization patter ns of the beta-tubulin sequences between stocks of the mexicana and br aziliensis complexes. There were similarities in the hybridization pat terns of different species of the mexicana complex. In contrast, a hig h heterogeneity was found between species of the braziliensis complex which includes intraspecific variation. The results suggest that this polymorphism may be associated with random mutations. The same analysi s gave evidence of large differences in the beta-tubulin gene restrict ion pattern between New and Old World Leishmania. This variation in th e beta-tubulin gene region was sufficient to distinguish between New a nd Old World Leishmania groups and between stocks of the mexicana and braziliensis complexes.