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Evolutionary history and molecular epidemiology of rabbit haemorrhagic disease virus in the Iberian Peninsula and Western Europe.

Alda F, Gaitero T, Suárez M, Merchán T, Rocha G, Doadrio I - BMC Evol. Biol. (2010)

Bottom Line: Evolutionary relationships of RHDV revealed three main lineages with significant phylogeographic structure.The Iberian Peninsula showed evidences of genetic isolation, probably due to geographic barriers to gene flow, and was also the region with the youngest MRCA.Overall, demographic analyses showed an initial increase and stabilization of the relative genetic diversity of RHDV, and a subsequent reduction in genetic diversity after the first epidemic breakout in 1984, which is compatible with a decline in effective population size.Consequently, this relationship is suggested to condition RHDV demographic history.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dpto Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain. alda.fernando@gmail.com

ABSTRACT

Background: Rabbit haemorrhagic disease virus (RHDV) is a highly virulent calicivirus, first described in domestic rabbits in China in 1984. RHDV appears to be a mutant form of a benign virus that existed in Europe long before the first outbreak. In the Iberian Peninsula, the first epidemic in 1988 severely reduced the populations of autochthonous European wild rabbit. To examine the evolutionary history of RHDV in the Iberian Peninsula, we collected virus samples from wild rabbits and sequenced a fragment of the capsid protein gene VP60. These data together with available sequences from other Western European countries, were analyzed following Bayesian Markov chain Monte Carlo methods to infer their phylogenetic relationships, evolutionary rates and demographic history.

Results: Evolutionary relationships of RHDV revealed three main lineages with significant phylogeographic structure. All lineages seem to have emerged at a common period of time, between ~1875 and ~1976. The Iberian Peninsula showed evidences of genetic isolation, probably due to geographic barriers to gene flow, and was also the region with the youngest MRCA.Overall, demographic analyses showed an initial increase and stabilization of the relative genetic diversity of RHDV, and a subsequent reduction in genetic diversity after the first epidemic breakout in 1984, which is compatible with a decline in effective population size.

Conclusions: Results were consistent with the hypothesis that the current Iberian RHDV arose from a single infection between 1869 and 1955 (95% HPD), and rendered a temporal pattern of appearance and extinction of lineages. We propose that the rising positive selection pressure observed throughout the history of RHDV is likely mediated by the host immune system as a consequence of the genetic changes that rendered the virus virulent. Consequently, this relationship is suggested to condition RHDV demographic history.

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Related in: MedlinePlus

Estimates of the tMRCA for the main geographical regions analyzed. Dots indicate median tMRCA values and blue lines represent 95% HPD.
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Figure 2: Estimates of the tMRCA for the main geographical regions analyzed. Dots indicate median tMRCA values and blue lines represent 95% HPD.

Mentions: When the main geographic regions were considered, the youngest tMRCA was recovered for the Iberian RHDV (~1936, 95% HPD 1955.7-1869.2) followed by the isolates from the UK (~1898, 95% HPD 1940.3-1822.5). The remnant regions showed wider 95% HPD intervals that were similar to the age of the complete RHDV data set (Figure 2).


Evolutionary history and molecular epidemiology of rabbit haemorrhagic disease virus in the Iberian Peninsula and Western Europe.

Alda F, Gaitero T, Suárez M, Merchán T, Rocha G, Doadrio I - BMC Evol. Biol. (2010)

Estimates of the tMRCA for the main geographical regions analyzed. Dots indicate median tMRCA values and blue lines represent 95% HPD.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992527&req=5

Figure 2: Estimates of the tMRCA for the main geographical regions analyzed. Dots indicate median tMRCA values and blue lines represent 95% HPD.
Mentions: When the main geographic regions were considered, the youngest tMRCA was recovered for the Iberian RHDV (~1936, 95% HPD 1955.7-1869.2) followed by the isolates from the UK (~1898, 95% HPD 1940.3-1822.5). The remnant regions showed wider 95% HPD intervals that were similar to the age of the complete RHDV data set (Figure 2).

Bottom Line: Evolutionary relationships of RHDV revealed three main lineages with significant phylogeographic structure.The Iberian Peninsula showed evidences of genetic isolation, probably due to geographic barriers to gene flow, and was also the region with the youngest MRCA.Overall, demographic analyses showed an initial increase and stabilization of the relative genetic diversity of RHDV, and a subsequent reduction in genetic diversity after the first epidemic breakout in 1984, which is compatible with a decline in effective population size.Consequently, this relationship is suggested to condition RHDV demographic history.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dpto Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain. alda.fernando@gmail.com

ABSTRACT

Background: Rabbit haemorrhagic disease virus (RHDV) is a highly virulent calicivirus, first described in domestic rabbits in China in 1984. RHDV appears to be a mutant form of a benign virus that existed in Europe long before the first outbreak. In the Iberian Peninsula, the first epidemic in 1988 severely reduced the populations of autochthonous European wild rabbit. To examine the evolutionary history of RHDV in the Iberian Peninsula, we collected virus samples from wild rabbits and sequenced a fragment of the capsid protein gene VP60. These data together with available sequences from other Western European countries, were analyzed following Bayesian Markov chain Monte Carlo methods to infer their phylogenetic relationships, evolutionary rates and demographic history.

Results: Evolutionary relationships of RHDV revealed three main lineages with significant phylogeographic structure. All lineages seem to have emerged at a common period of time, between ~1875 and ~1976. The Iberian Peninsula showed evidences of genetic isolation, probably due to geographic barriers to gene flow, and was also the region with the youngest MRCA.Overall, demographic analyses showed an initial increase and stabilization of the relative genetic diversity of RHDV, and a subsequent reduction in genetic diversity after the first epidemic breakout in 1984, which is compatible with a decline in effective population size.

Conclusions: Results were consistent with the hypothesis that the current Iberian RHDV arose from a single infection between 1869 and 1955 (95% HPD), and rendered a temporal pattern of appearance and extinction of lineages. We propose that the rising positive selection pressure observed throughout the history of RHDV is likely mediated by the host immune system as a consequence of the genetic changes that rendered the virus virulent. Consequently, this relationship is suggested to condition RHDV demographic history.

Show MeSH
Related in: MedlinePlus