DISPLAY OF SEQUENCE VARIATION IN PCR-AMPLIFIED MITOCHONDRIAL-DNA REGIONS OF ECHINOCOCCUS BY SINGLE-STRAND CONFORMATION POLYMORPHISM

Echinococcosis, a disease caused by infection with the larval stage of a tapeworm parasite of the genus Echinococcus, is of major socio-econ omic importance, and studying genetic variability within and between E chinococcus populations has important implications for disease control and epidemiology. Various DNA approaches have been used to study Echi nococcus genetics, but most methods do not allow the accurate display or definition of mutational/allelic variation. To overcome this limita tion, we established a mutation scanning approach. Single-strand confo rmation polymorphism (SSCP) of two different enzymatically amplified m itochondrial (mt) DNA regions was evaluated using seven different geno types of Echinococcus (defined as G1, G4, G6, G8, O, V and M2). The NA DH dehydrogenase 1 gene (ND1) or the cytochrome c oxidase subunit 1 (C O1) were amplified by polymerase chain reaction from parasite DNA, den atured and directly subjected to electrophoresis in a non-denaturing g el matrix. Each of the seven genotypes examined could be delineated fr om one another based on characteristic and reproducible banding patter ns. The results demonstrate the usefulness of SSCP for the direct visu al display of sequence variation in mtDNA of Echinococcus without the need for DNA sequencing or restriction analyses, and indicate its pote ntial for studying allelic variability in a range of other genes. (C) 1998 Elsevier Science B.V. All rights reserved.