Echinococcus granulosus: intraspecific genetic variation assessed by a DNA repetitive element

MARA CECILIA ROSENZVIT; CANOVA, S.; KAMENETZKY, L.; GUARNERA, E.

PARASITOLOGY

Año: 2001 vol. 123 p. 381 - 388

0031-1820

A 186 bp Echinococcus granulosus-specific repetitive element, TREg, was used toassess genetic variation between strains. In G7 genotype (pig strain) it has the characteristics of a satellite DNA element with a copy number of 23000 perhaploid genome. Analysis, by sequencing of TREg monomers, showed a great degreeof identity within them. In the G1 genotype (common sheep strain) TREg-likerepetitive elements were found in an interspersed distribution throughout thegenome and in only 120 copies. The sequences of these monomers showed a greatdegree of variation between them and with TREg of G7 origin. The G6 genotype(camel strain) showed a pattern of distribution and copy number similar to the G7genotype, and the G2 genotype (Tasmanian sheep strain) similar to the G1genotype. Isolates from the G5 (cattle strain) and G4 (horse strain) genotypesalso showed unique hybridization patterns in Southern blot experiments. Thegenomic plasticity of E. granulosus, which may have important consequences in theepidemiology and control of cystic hydatid disease is reflected in the results ofthis work.