Isolation and characterization of microsatellites from the tapeworm Echinococcus granulosus

BARTHOLOMEI-SANTOS M. L.; HEINZELMANN L. S.; OLIVEIRA R. P.; CHEMALE G.; GUTIERREZ A. M.; KAMENETZKY L.; HAAG K. L.; ZAHA A.

PARASITOLOGY

Cambridge University Press

Lugar: Reino Unido; Año: 2003 vol. 126 p. 599 - 605

0031-1820

SUMMARY The Echinococcus granulosus genome was searched for microsatellites using eight different repeated oligonucleotides as probes (GT15, CT15, AT15, CG15, CAT10, CAA10, CGG10 and CATA10). Southern blot experiments revealed that DNA regions containing GT, CAA, CATA and CT repeats are the most frequent in the E. granulosus genome. AT and CG probes showed no hybridization signal. Two loci containing CA/GT (Egmsca1 and Egmsca2) and one locus containing GA/CT (Egmsga1) repeats were cloned and sequenced. The locus Egmsca1 was analyzed in 73 isolates from Brazil and Argentina whose strains were previously characterized. Brazilian isolates from cattle strain and Argentinean isolates from camel strain were monomorphic and shared the allele (CA)7. Argentinean isolates of sheep and Tasmanian sheep strains shared two alleles [(CA)8 and (CA)10] with Brazilian isolates of sheep strain. The allele (CA)11 was found only in Brazilian isolates of sheep strain at a low frequency. The Brazilian and the Argentinean sheep strain populations were tested for the Hardy-Weinberg equilibrium, and only the former was in agreement with the expectations. No ,polymorphism was found among individual protoscoleces from a single hydatid cyst, validating the utilization of pooled protoscoleces from one cyst, grouped as an isolate, in population studies. This work describes for the first time the isolation and characterization of microsatellites from E. granulosus.