Trophozoite and nuclear size, DNA base composition, and nucleotide sequence homology of several Entamoeba strains in axenic culture (original) (raw)

Abstract

We carried out a comparative study of nuclear and trophozoite diameters and of DNA thermal denaturation in eight Entamoeba strains cultured axenically (four of them E. histolytica, two initially designated as E. invadens, one E. moshkovskii, and one _E. histolytica_-like), as well as an analysis of the overall DNA sequence homology of the non-E. histolytica strains. The average nuclear (N) and trophozoite (T) diameters (in Μm) were, respectively: global averages ±SD for E. histolytica strains, 6.5±2.5 and 28.8±3.7; E. invadens IP101, 5.8 and 27.5, and PZ, 7.8 and 33.6; E. moshkovskii FIC, 4.1 and 12.9; E. histolytica- like Laredo strain, 5.0 and 20.6. The GC content of DNA, estimated by thermal elution in hydroxyapatite, was around 23% in HK9 and its clone HK9-1 and around 27% in the HM2 and HM3 E. histolytica strains; it was 37% in the Laredo strain, 26% in IP101, 35% in PZ, and 33% in FIC. The reassociation kinetics of PZ strain DNA showed that it consists of 40% repeated sequences and 60% unique sequences. By means of DNA association experiments in which one of each pair of DNAs tested had been labeled in vitro with 125I, we found the following overall sequence homology among the strains tested: PZ-FIC, 38%; IP101-Laredo, 38%; IP101-FIC, 47%; PZ-Laredo, 49%; Laredo-FIC, 69%; and IP101-PZ, 83%. We conclude that trophozoites of different E. histolytica strains have similar nuclear size and GC content, whereas these parameters and the nucleotide sequences are clearly different in every other Entamoeba species. Our data also suggest that PZ and IP101 strains do not belong to the same species.

Access this article

Log in via an institution

Subscribe and save

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

Download references

Author information

Authors and Affiliations

  1. Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Ap. Postal 14-740, 07000, México, D.F., México
    R. López-Revilla & R. Gómez-Domínguez

Authors

  1. R. López-Revilla
  2. R. Gómez-Domínguez

Rights and permissions

About this article

Cite this article

López-Revilla, R., Gómez-Domínguez, R. Trophozoite and nuclear size, DNA base composition, and nucleotide sequence homology of several Entamoeba strains in axenic culture.Parasitol Res 74, 424–430 (1988). https://doi.org/10.1007/BF00535141

Download citation

Keywords