Arbitrarily primed PCR fingerprinting of RNA and DNA in Entamoeba histolytica

Abstract

Differences were detected in the gene expression of strains of E. histolytica using RNA (RAP-PCR) and DNA fingerprinting (RAPD). Analysis of the electrophoretic profiles of the gels revealed some polymorphic markers that could be used in the individual characterization of the strains. The 260 bands generated by using five different primers for RAP-PCR, as well as RAPD, were employed in the construction of dendograms. The dendogram obtained based on the RAPD products permitted the distinction of symptomatic and asymptomatic isolates, as well the correlation between the polymorphism exhibited and the virulence of the strains. The dendogram obtained for the RAP-PCR products did not show a correlation with the virulence of the strains but revealed a high degree of intraspecific transcriptional variability that could be related to other biological features, whether or not these are involved in the pathogenesis of amebiasis.

Comparative Genomic Hybridizations ofEntamoebaStrains Reveal Unique Genetic Fingerprints That Correlate with Virulence

“…One previous study using RAPD also identified EH (Rahman) as distinct from virulent EH strains (64). However, unlike our study, they were not able to identify the genetic regions that differentiated EH (Rahman) from the other EH strains.…”

“…Although limited, these data indicate that the extensive genetic diversity identified by analysis of repetitive regions may not be indicative of a genome-wide phenomenon. A number of studies have attempted to identify an association between parasite genotype and the clinical phenotype and although most have failed, two studies (one using RAPD analysis of amebic isolates and one using PCR and RFLP analyses of the serine-rich E. histolytica protein [SREHP]) did give some preliminary indication that it may be feasible to find a genotypic pattern predictive of a phenotypic outcome (7,64). Host factors that contribute to variable disease manifestations have also been studied.…”

“…Studies have analyzed a small number of highly repetitive and polymorphic genetic loci by techniques, such as randomly amplified polymorphic DNA (RAPD), RNA arbitrarily primed PCR, and restriction fragment length polymorphism (RFLP), to conclude that there is significant genetic diversity (7,18,23,31,33,64,72,73). Contradictory data were obtained by two studies; in one study, the lectin gene was sequenced, and in the other study, the intergenic region between the superoxide dismutase gene and the actin 3 gene was analyzed (9,30).…”

Coding and Noncoding Genomic Regions of Entamoeba histolytica Have Significantly Different Rates of Sequence Polymorphisms: Implications for Epidemiological Studies

“…Analyses of nonrepetitive loci have revealed very limited polymorphisms (3,6). There is no definitive correlation between genotypes of E. histolytica strains and their clinical manifestations; however, three studies preliminarily indicated that genotypic patterns may be predictive of a clinical outcome (1,16,18). To get an improved perspective of genetic variability in nonrepetitive genomic regions, we sequenced 9,077 bp (6,621 bp coding and 2,456 bp noncoding) from each of 14 E. histolytica isolates.…”

DNA polymorphism in the living fossil Ginkgo biloba from the Eastern United States

“…The amplification products are then resolved in gels and recorded by a variety of techniques (reviewed in Caetano-Anolles 1996). Presence or absence of DNA bands in the gel may be used as RAPD markers to study inter-and intra-specific genetic variations (M'Ribu and Hilu 1994), for the identification of specific genes (Paran et al 1991;Martin et al 1991), and to study the pattern of gene expression (Valle et al 2000). Our results with a limited number of G. biloba specimens indicated a high degree of genetic homogeneity among plants grown in certain areas, although high levels of overall genetic diversity may exist in the species.…”