Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review

Rabbit haemorrhagic disease virus (RHDV) is a calicivirus of the genus Lagovirus that causes rabbit haemorrhagic disease (RHD) in adult European rabbits (Oryctolagus cuniculus). First described in China in 1984, the virus rapidly spread worldwide and is nowadays considered as endemic in several countries. In Australia and New Zealand where rabbits are pests, RHDV was purposely introduced for rabbit biocontrol. Factors that may have precipitated RHD emergence remain unclear, but non-pathogenic strains seem to pre-date the appearance of the pathogenic strains suggesting a key role for the comprehension of the virus origins. All pathogenic strains are classified within one single serotype, but two subtypes are recognised, RHDV and RHDVa. RHD causes high mortality in both domestic and wild adult animals, with individuals succumbing between 48-72 h post-infection. No other species has been reported to be fatally susceptible to RHD. The disease is characterised by acute necrotising hepatitis, but haemorrhages may also be found in other organs, in particular the lungs, heart, and kidneys due to disseminated intravascular coagulation. Resistance to the disease might be explained in part by genetically determined absence or weak expression of attachment factors, but humoral immunity is also important. Disease control in rabbitries relies mainly on vaccination and biosecurity measures. Such measures are difficult to be implemented in wild populations. More recent research has indicated that RHDV might be used as a molecular tool for therapeutic applications. Although the study of RHDV and RHD has been hampered by the lack of an appropriate cell culture system for the virus, several aspects of the replication, epizootology, epidemiology and evolution have been disclosed. This review provides a broad coverage and description of the current knowledge on the disease and the virus

The non-ratification of mixed agreements: Legal consequences and solutions

The 2016 referendum in the Netherlands on the EU-Ukraine Association Agreement and the Walloon objection in Belgium to sign CETA triggered the question of the consequences of the non-ratification of mixed agreements that are (to be) concluded between the EU, its Member States and one or more third parties. This non-ratification would lead to so-called "incomplete" mixed agreements. The present article discusses the legal problems connected to incomplete agreements and points to the differences between bilateral and multilateral agreements. Now that mixity seems to be have become more common - due to the wider scope of Free Trade Agreements - and EU citizens and their parliaments become more outspoken with respect to the content of these agreements, it seems just a matter of time before we are faced with problems of non-ratification. The unclear division of external competences between the EU and its Member States makes it difficult to offer clear-cut solutions. Overall, however, it does not seem advisable to rely on ex post facto solutions for non-ratification problems; we may have to find ways to allow potential problems to be on the negotiation table at an earlier stage

Pseudogenization of the MCP-2/<it>CCL8</it> chemokine gene in European rabbit (genus <it>Oryctolagus</it>), but not in species of Cottontail rabbit (<it>Sylvilagus</it>) and Hare (<it>Lepus</it>)

<p>Abstract</p> <p>Background</p> <p>Recent studies in human have highlighted the importance of the monocyte chemotactic proteins (MCP) in leukocyte trafficking and their effects in inflammatory processes, tumor progression, and HIV-1 infection. In European rabbit (<it>Oryctolagus cuniculus</it>) one of the prime MCP targets, the chemokine receptor CCR5 underwent a unique structural alteration. Until now, no homologue of MCP-2/<it>CCL8</it>^a, MCP-3/<it>CCL7</it> or MCP-4/<it>CCL13</it> genes have been reported for this species. This is interesting, because at least the first two genes are expressed in most, if not all, mammals studied, and appear to be implicated in a variety of important chemokine ligand-receptor interactions. By assessing the Rabbit Whole Genome Sequence (WGS) data we have searched for orthologs of the mammalian genes of the MCP-Eotaxin cluster.</p> <p>Results</p> <p>We have localized the orthologs of these chemokine genes in the genome of European rabbit and compared them to those of leporid genera which do (<it>i.e</it>. <it>Oryctolagus</it> and <it>Bunolagus</it>) or do not share the CCR5 alteration with European rabbit (<it>i.e. Lepus</it> and <it>Sylvilagus</it>). Of the Rabbit orthologs of the <it>CCL8</it>, <it>CCL7</it>, and <it>CCL13</it> genes only the last two were potentially functional, although showing some structural anomalies at the protein level. The ortholog of MCP-2/<it>CCL8</it> appeared to be pseudogenized by deleterious nucleotide substitutions affecting exon1 and exon2. By analyzing both genomic and cDNA products, these studies were extended to wild specimens of four genera of the <it>Leporidae</it> family: <it>Oryctolagus</it>, <it>Bunolagus, Lepus,</it> and <it>Sylvilagus</it>. It appeared that the anomalies of the MCP-3/<it>CCL7</it> and MCP-4/<it>CCL13</it> proteins are shared among the different species of leporids. In contrast, whereas MCP-2/<it>CCL8</it> was pseudogenized in every studied specimen of the <it>Oryctolagus</it> - <it>Bunolagus</it> lineage, this gene was intact in species of the <it>Lepus</it> - <it>Sylvilagus</it> lineage, and was, at least in <it>Lepus</it>, correctly transcribed.</p> <p>Conclusion</p> <p>The biological function of a gene was often revealed in situations of dysfunction or gene loss. Infections with Myxoma virus (MYXV) tend to be fatal in European rabbit (genus <it>Oryctolagus</it>), while being harmless in Hares (genus <it>Lepus</it>) and benign in Cottontail rabbit (genus <it>Sylvilagus</it>), the natural hosts of the virus. This communication should stimulate research on a possible role of MCP-2/<it>CCL8</it> in poxvirus related pathogenicity.</p

The ratification saga of the EU-Ukraine Association Agreement : some lessons for the practice of mixed agreements

On 6 April 2016, a referendum on the approval of the Association Agreement between the European Union (EU), its Member States and Ukraine was organised in the Netherlands. Despite its non-binding nature, the outcome of the referendum created significant political and legal problems. Politically speaking, Dutch governmental and parliamentary representatives had committed themselves to take the result of the referendum seriously, implying that the mere continuation of the internal ratification process was not an option. Consequently, several legal problems emerged since the EU-Ukraine Association Agreement could only enter into force upon the approval of all parties. Although it already happened in the past that a third country failed to ratify a mixed agreement with the EU, leading to the addition of an adjustment protocol clarifying that this country would not become a party to the agreement, the situation after the Dutch referendum was significantly more complicated. For the first time, an EU Member State was on the verge of not ratifying a mixed agreement. Without a solution for the Dutch situation, the Council could not adopt the final Decision regarding the conclusion of the agreement. At the same time, however, a significant part of the agreement had already provisionally entered into force raising questions about the limits of this practice

An overview of the lagomorph immune system and its genetic diversity.

Our knowledge of the lagomorph immune system remains largely based upon studies of the European rabbit (Oryctolagus cuniculus), a major model for studies of immunology. Two important and devastating viral diseases, rabbit hemorrhagic disease and myxomatosis, are affecting European rabbit populations. In this context, we discuss the genetic diversity of the European rabbit immune system and extend to available information about other lagomorphs. Regarding innate immunity, we review the most recent advances in identifying interleukins, chemokines and chemokine receptors, Toll-like receptors, antiviral proteins (RIG-I and Trim5), and the genes encoding fucosyltransferases that are utilized by rabbit hemorrhagic disease virus as a portal for invading host respiratory and gut epithelial cells. Evolutionary studies showed that several genes of innate immunity are evolving by strong natural selection. Studies of the leporid CCR5 gene revealed a very dramatic change unique in mammals at the second extracellular loop of CCR5 resulting from a gene conversion event with the paralogous CCR2. For the adaptive immune system, we review genetic diversity at the loci encoding antibody variable and constant regions, the major histocompatibility complex (RLA) and T cells. Studies of IGHV and IGKC genes expressed in leporids are two of the few examples of trans-species polymorphism observed outside of the major histocompatibility complex. In addition, we review some endogenous viruses of lagomorph genomes, the importance of the European rabbit as a model for human disease studies, and the anticipated role of next-generation sequencing in extending knowledge of lagomorph immune systems and their evolution.This work is funded by national funds through FCT—Foundation for Science and Technology—under the project FCT-ANR/BIA-BIC/0043/2012. FCT also supported the doctoral fellowships of FN and AP (refs. SFRH/BD/81916/2011 and SFRH/BD/71252/2010) and the investigator grant of JA (ref. IF/01396/2013). This work is funded also by FEDER funds through the Operational Programme for Competitiveness Factors—COMPETE and by National Funds through FCT—Foundation for Science and Technology under the project PTDC/BIA-ANM/3963/2012 and FCOMP-01-0124-FEDER-028286 and “Genomics Applied To Genetic Resources” co-financed by North Portugal Regional Operational Programme 2007/2013 (ON.2-O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). RGM was partially supported by the Intramural Research Program of the NIAID, NIH.Peer Reviewe