Why the Myxoma virus infection is highly lethal for the European rabbit (Oryctolagus cuniculus), while in other leporids it is benign?

The major question that we intend to answer is why is the European rabbit (Oryctolagus cuniculus) infected by the Myxoma virus (MV), causing a severe and lethal disease, while in other leporids genera the MV infection is benign. Our main working hypothesis is: the genes targeted by the viral immunoregulatory proteins should be strike by evolutionary forces that lead to host adaptations and, consequently, change its susceptibility to the pathogen. This would explain the differences among the leporids, namely between Sylvilagus and Oryctolagus, to the MV infection susceptibility or resistance. To disclose this, our strategy consists in the comparison of the genetic diversity of candidate genes underlying the variable susceptibility to MV in European rabbit populations as well as in other leporids. Indeed, we already observed structural differences in chemokine receptors CCR5 and CXCR4 proteins between the European rabbit and other leporids. Through this comparison we hope to: i) understand the several mechanisms driving the evolution of these genes within and between species; ii) detect possible advantageous alleles within European rabbit populations; iii) prove, in vitro, that genetic differences within or between the analysed species lead to a different viral binding ability. Additionally, it should also be important to understand the expression pattern of these candidate genes in the tissues targeted by the MV.