Genetic diversity and evolution of Hare Calicivirus (HaCV), a recently identified lagovirus from Lepus europaeus

First recognized as highly pathogenic viruses, hare lagoviruses belonging to genotype GII.1 (EBHSV) infect various Lepus species. Genetically distinct benign lagoviruses (Hare Calicivirus, HaCV) have recently been identified but few data have been available so far on these strains. The analysis of 199 samples from hunted hares collected throughout France allowed the detection of 20 HaCV and showed that they were widely distributed in this country. Ten HaCV capsid protein gene sequences were characterized. A first HaCV capsid protein structural model was proposed, revealing a global structure similar to that of a pathogenic GII.1 strain. The HaCV sequences showed an even higher genetic diversity than previously appreciated, with the characterization of two genotypes (GII.2, GII.3) and several additional putative genotypes. The most recent common ancestor for HaCV VP60 gene was estimated to be much older than that for GII.1 pathogenic strains. These results give new insights into the phylogenetic relationships of HaCV within the Lagovirus genus.