Molecular karyotype of related clones of Entamoeba histolytica.
The molecular karyotype of 3 clones derived from strain HM1:IMSS of Entamoeba histolytica was studied by transverse alternating field electrophoresis. 11-20 bands ranging between 0.3 and over 3 Mb were resolved. Hybridization with total DNA detected highly repetitive sequences in the slow-migrating molecules, while non-repetitive sequences were located in the intermediate and fast-migrating molecules. rDNA, tubulin, actin, cysteine proteases DNA fragments, and a variable DNA sequence (EhVR1) located the respective genes mainly in the 1.3-1.5-Mb region, although they differed in the three clones. Two-dimensional transverse alternating field electrophoresis showed that more than one high-molecular weight molecule may comigrate in a single DNA band. rDNA, and EhVR1 hybridized with slow-migrating bands in a characteristic ladder pattern. Most of the bands recognized by EhVR1 seems to be linear molecules, although exonuclease III-resistant bands also hybridized with EhVR1, suggesting the presence of circles.
Orozco
E
E
Department of Experimental Pathology, Centro de Investigación y de Estudios Avanzados del I.P.N., Mexico City, Mexico.
Báez-Camargo
M
M
Gamboa
L
L
Flores
E
E
Valdés
J
J
Hernández
F
F
D000199:Actins / Q000235:genetics; D000818:Animals; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics* / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000235:genetics; D004748:Entamoeba histolytica / Q000235:genetics*; D017125:Genes, Protozoan; D005838:Genotype; D010641:Phenotype; D011110:Polymorphism, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D014404:Tubulin / Q000235:genetics
D000199:Actins; D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D014404:Tubulin; D003546:Cysteine Endopeptidases