Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 May;51(6):471-480.
doi: 10.1016/j.ijpara.2020.11.007. Epub 2021 Feb 11.

Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina

Nicola J Beesley  1 , Elizabeth Attree  2 , Severo Vázquez-Prieto  3 , Román Vilas  4 , Esperanza Paniagua  5 , Florencio M Ubeira  5 , Oscar Jensen  6 , Cesar Pruzzo  7 , José D Álvarez  8 , Jorge Bruno Malandrini  9 , Hugo Solana  10 , Jane E Hodgkinson  2
Affiliations

Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina

Nicola J Beesley et al. Int J Parasitol. 2021 May.

Abstract

Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise FST values amongst all four provinces were significant, with standardised pairwise FST (F'ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy-Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.

Keywords: Argentina; Clones; Fasciola hepatica; Population genetics; Population structure.

PubMed Disclaimer

Figures

None
Graphical abstract
Fig. 1
Fig. 1
Provincial map of Argentina detailing the locations of sampling sites. Labels match those listed in Table 1.
Fig. 2
Fig. 2
Results from Structure 2.3.4 (Pritchard et al., 2000), the admixture model (alternative prior, ALPHA allowed to vary for each population and an initial value of ALPHA of 0.0714) with the correlated allele frequency model was run 20 times for K = 1 to 14. Burn-in length was 500,000 followed by 100,000 Markov Chain Monte Carlo repeats. (A) The mean ± standard deviation of the estimated Ln probability is plotted for each value of K. The peak is at K = 3. (B) Bar plot from Structure 2.3.4 for K = 3. Results are grouped by province. There is strong clustering by region: parasites from Corrientes, parasites from Entre Ríos, and parasites from Catamarca and Chubut.
Fig. 3
Fig. 3
Result of principal coordinate analysis (PCoA) based on a pairwise genetic distance matrix between each individual parasite and the standardised covariance method was performed in Genalex v6.51b2 (Peakall and Smouse, 2006, Peakall and Smouse, 2012). PCoA analysis also shows population structure; this is particularly evident in parasites from Corrientes (triangles), however parasites from Chubut (squares) and Entre Ríos (circles) also show separation on axis 2.
See this image and copyright information in PMC

References

    1. Abrous M., Vareille-Morel C., Rondelaud D., Dreyfuss G., Cabaret J. Metacercarial aggregation in Digenea (Fasciola hepatica and Paramphistomum daubneyi): environmental or species determinism? J. Helminthol. 2001;75:307–311. doi: 10.1017/S0022149X01000476. - DOI - PubMed
    1. Arnaud-Haond, S., Belkhir, K. 2007. GENCLONE: a computer program to analyse genotypic data, test for clonality and describe spatial clonal organization. Mol. Ecol. Notes. 7, 15–17. doi: 10.1111/j.1471-8286.2006.01522.x.
    1. Aznar M.N., Stevenson M.A., Zarich L., León E.A. Analysis of cattle movements in Argentina, 2005. Prev. Vet. Med. 2011;98:119–127. doi: 10.1016/j.prevetmed.2010.11.004. - DOI - PubMed
    1. Bargues M.D., Malandrini J.B., Artigas P., Soria C.C., Velásquez J.N., Carnevale S., Mateo L., Khoubbane M., Mas-Coma S. Human fascioliasis endemic areas in Argentina: multigene characterisation of the lymnaeid vectors and climatic-environmental assessment of the transmission pattern. Parasites Vectors. 2016;9 doi: 10.1186/s13071-016-1589-z. - DOI - PMC - PubMed
    1. Beesley N.J., Williams D.J.L., Paterson S., Hodgkinson J. Fasciola hepatica demonstrates high levels of genetic diversity, a lack of population structure and high gene flow: possible implications for drug resistance. Int. J. Parasitol. 2017;47:11–20. doi: 10.1016/j.ijpara.2016.09.007. - DOI - PMC - PubMed

Publication types

LinkOut - more resources