Glycobiology Advance Access originally published online on October 8, 2008
Glycobiology 2009 19(1):21-28; doi:10.1093/glycob/cwn098
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Association between expression of the H histo-blood group antigen,
1,2fucosyltransferases polymorphism of wild rabbits, and sensitivity to rabbit hemorrhagic disease virus
2 INSERM, U892, Université de Nantes
3 Ecole Nationale Vétérinaire de Nantes
4 Office National de la Chasse et de la Faune Sauvage, Nantes, France
1 To whom correspondence should be addressed: Tel: +33-240-08-40-99; Fax: +33-240-08-40-82; e-mail: jlependu{at}nantes.inserm.fr
Received on August 21, 2008; revised on September 23, 2008; accepted on September 23, 2008
RHDV (rabbit hemorrhagic disease virus) is a highly virulent calicivirus that has become a major cause of mortality in wild rabbit populations (Oryctolagus cuniculus). It binds to the histo-blood group antigen (HBGA) H type 2 which requires an
1,2fucosyltransferase for its synthesis. In rabbit, three
1,2fucosyltransferases genes are known, Fut1, Fut2, and Sec1. Nonfunctional alleles at any of these loci could potentially confer resistance to RHDV, similar to human FUT2 alleles that determine the nonsecretor phenotype and resistance to infection by various NoV strains. In this study, we looked for the presence of H type 2 on buccal epithelial cells of wild rabbits from two geographic areas under RHDV pressure and from one RHDV-free area. Some animals with diminished H type 2 expression were found in the three populations (nonsecretor-like phenotype). Their frequency markedly increased according to the RHDV impact, suggesting that outbreaks selected survivors with low expression of the virus ligand. Polymorphisms of the Fut1, Fut2, and Sec1 coding regions were determined among animals that either died or survived outbreaks. The Fut2 and Sec1 genes presented a high polymorphism and the frequency of one Sec1 allele was significantly elevated, over 6-fold, among survivors. Sec1 enzyme variants showed either moderate, low, or undetectable catalytic activity, whereas all variant Fut2 enzymes showed strong catalytic activity. This functional analysis of the enzymes encoded by each Fut2 and Sec1 allele suggests that the association between one Sec1 allele and survival might be explained by a deficit of
1,2fucosyltransferase expression rather than by impaired catalytic activity.
Key words: fucosyltransferase / histo-blood group antigens / polymorphism / resistance to pathogens / RHDV