FP6 priority

1.1.1   Genomics and Biotechnology for Health

1.1.1.1

Title of the proposal

Population biology of metazoan parasites and application of genetic markers

Institute

Slovak Academy of Sciences, Parasitological Institute
Hlinkova 3, 04001 Kosice, Slovak Republic

Contact

Research subject for a potential FP6 project

Understanding mechanisms behind the changes in population genetics of animals has many implications, particularly in estimating fitness and viability of populations and in evaluating how organisms may respond to control based on chemotherapy and vaccination. Knowing which features of life cycles are most important in determining genetic structure would allow to explain and predict important evolutionary processes such as adaptation to environment, modes of speciation, and the nature of breeding systems. Evolution of resistance to drugs in parasites has in many cases grown to an important economical problem and population genetics have not yet been adequately utilized in clarifying the mechanisms of resistance. This approach involves measurement of allele frequencies at candidate genes before and after selection. Population genetic surveys are also desirable in understanding the probability for the dissemination of novel anthelmintic resistance mutations over geographical space and time. In addition, there are currently few comparative data on the genetic composition of different parasite species that differ in key features of their life cycles, zoonotic potential or other important aspects. Diversity should be a direct function of effective population size when assayed using neutral markers. If the reverse is true, selection forces influence patterns of genetic heterogeneity. Comparative population studies of species of interest using similar sampling designs and same molecular markers are therefore needed. If most loci show panimictic distribution and one reveal subdivision, a likely explanation is that selection maintains allele frequency differences between populations in the face of high level of gene flow. Conversely, a lack of population structure at some loci may indicate balancing selection. Parasites represent interesting models for investigation at the population level due to involvement of host phenomenon and complexity of their life cycles. Revealing the genetic architecture of helminth populations and factors that account for the selection might aid in designing control strategies to more effectively eradicate them from the environment. For effective diagnosis and treatment of parasite infections, individuals should be accurately identified beyond the species level, with different strains (if occur) being recognised. Within the project, DNA-based approaches are intended to use as the differentiating tool for parasites of socio-economical importance, isoenzyme-based techniques will be applied for population studies. To compare genetic and phenotypical variation, morphological traits will be investigated using traditional methods. In vitro techniques (e.g., egg hatch assay, larval development assay) will be used for a primary detection of anthelminthic resistant strains. These will be further investigated at the molecular level in order to shed more light to the mechanisms responsible for acquiring resistance.

Recent international cooperation of the research team

Istituto di Parassitologia, Universita La Sapienza; Rome, Italy
Danish Centre for Experimental Parasitology, Royal Agricultural and Veterinary University; Copenhagen, Denmark
Station de Patholologie Aviaire et de Parasitologie, INRA; Nouzilly, France
Institut fur Parasitologie, Tieraztliche Hohschule; Hannover, Germany

Proposer´s relevant publications related to the research subject

SNABEL V., MALAKAUSKAS A., DUBINSKY P., KAPEL C.M.O. (2001): Estimating the genetic divergence and identification of three Trichinella species by isoenzyme analysis. Parasite 8, S30-S33.
SNABEL V., PERMIN A., MAGWISHA H.B., SUO X., VARADY M., TOMASOVICOVA O. (2001): On the species identity of Ascaridia galli (Schrank, 1788) and Ascaridia dissimilis (Perez Vigueras, 1931): a comparative genetic study. Helminthologia 38, 221-226.
SNABEL V., DE MEEÛS T., VARADY M., NANSEN P., BJØRN H., CORBA J. (2000): Sexually linked Mpi locus is presumably involved in imidothiazole resistance in Oesophagostomum dentatum parasites. Parasitology Research 86, 486-490.
SNABEL V., D'AMELIO S., MATHIOPOULOS K., TURCEKOVA L., DUBINSKY P. (2000): Molecular evidence for the presence of a G7 genotype of Echinococcus granulosus in Slovakia. Journal of Helminthology 74, 177-181.