title: Species- and strain-specific probes derived from repetitive DNA for distinguishing Entamoeba histolytica and Entamoeba dispar.
abstract: Entamoeba histolytica and Entamoeba dispar are two morphologically indistinguishable species that are found in the human gut. Of the two, E. histolytica is considered to be pathogenic while E. dispar is nonpathogenic. To generate molecular probes to detect and distinguish between the two species, we utilized repeat sequences present in Entamoeba genome. We have developed probes and primers from rDNA episomes, and unidentified Entamoeba EST1 repeat for this purpose, and used them for dot blot hybridization and PCR amplification. To investigate the possible existence of invasive and noninvasive strains of E. histolytica, the ability to differentiate individual isolates is necessary. For this purpose, we have utilized a modification of the AFLP procedure called 'Transposon display,' which generates and displays large number of genomic bands associated with a transposon. We have used the abundant retrotransposon, EhSINE1, for this purpose,and demonstrated its potential as a marker to study strain variation in E. histolytica. This technique could suitably be employed in carrying out significant molecular epidemiological studies and large-scale typing of this parasite.
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Srivastava
authors.forename: Sudha
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Jaishree
authors.initials: J
authors.lastname: Paul
mesh_terms: D000818:Animals; D017931:DNA Primers / Q000737:chemistry / Q000592:standards; D015342:DNA Probes / Q000737:chemistry / Q000592:standards*; D004251:DNA Transposable Elements / Q000235:genetics; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics*; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004747:Entamoeba / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004748:Entamoeba histolytica / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D015151:Immunoblotting; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D015183:Restriction Mapping; D020086:Short Interspersed Nucleotide Elements / Q000235:genetics; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D015342:DNA Probes; D004251:DNA Transposable Elements; D016054:DNA, Protozoan; D004275:DNA, Ribosomal