Minichromosomal repetitive DNA in Trypanosoma cruzi: Its use in a high-sensitivity parasite detection assay

We have isolated genomic clones containing members of a tandemly repeated DNA family from Trypanosoma cruzi. This family, which contains a 195-base pair (bp) repeating unit, is the most abundant repetitive DNA in this organism. DNA sequencing analysis of three adjacent tandem repeats as well as two...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 1984-06, Vol.81 (11), p.3356-3360
Main Authors: Gonzalez, A, Prediger, E, Huecas, M.E, Nogueira, N, Lizardi, P.M
Format: Article
Language:English
Subjects:
Base Sequence
Blood
Cellulose nitrate
Chagas Disease - diagnosis
Chagas Disease - genetics
chromosomes
disease diagnosis
DNA
DNA probes
Extrachromosomal Inheritance
Gels
Genetic hybridization
genetics
Genomes
Humans
Kinetoplast DNA
Nucleic acids, Protozoa
Open reading frames
Protozoa
protozoal infections
Repetitive Sequences, Nucleic Acid
Sodium
Species Specificity
Trypanosoma cruzi
Trypanosoma cruzi - genetics
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We have isolated genomic clones containing members of a tandemly repeated DNA family from Trypanosoma cruzi. This family, which contains a 195-base pair (bp) repeating unit, is the most abundant repetitive DNA in this organism. DNA sequencing analysis of three adjacent tandem repeats as well as two independent nonadjacent repeats showed relatively little sequence heterogeneity. Surprisingly, the three tandem elements contained a 585-bp open reading frame. However, blot hybridization of RNA from epimastigotes as well as blood-form trypomastigotes failed to show evidence for transcription of these sequences. Fractionation of whole T. cruzi DNA in sucrose gradients or in agarose gels followed by hybridization with appropriate radioactive probes showed that the size distribution of DNA bearing the 195-bp repetitive element is distinct from that of kinetoplast DNA as well as from that of DNA bearing tubulin genes. Hybridization of the 195-bp element probe with DNA from six different T. cruzi strains was positive; hybridization with DNA of other protozoa was negative with the single exception of Leptomonas collosoma, which displayed a weak cross-hybridization signal. Clones bearing this repetitive element are shown to be useful as probes for identification and counting of T. cruzi cells by dot-blot hybridization. The sensitivity of this assay permits detection of the DNA of 30 parasites in blood samples.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.81.11.3356