Avian metapneumovirus (AMPV) infection of poultry causes serious disease in most countries and subtype A reverse-genetic (RG) systems have allowed a generation of viruses of known sequence, and proved useful in developments towards better control by live vaccines. While subtype B viruses are more prevalent, bacterial cloning issues made subtype B RG systems difficult to establish. A molecular comparison of subtype A and B viruses was undertaken to assess whether subtype A RG components could be partially or fully substituted. AMPV subtype A and B gene-end sequences leading to polyadenylation are, to our knowledge, reported for the first time, as well as several leader and trailer sequences. After comparing these alongside previously reported gene starts and protein sequences, it was concluded that subtype B genome copies would be most likely rescued by a subtype A support system, and this assertion was supported when individual subtype A components were successfully substituted. Application of an advanced cloning plasmid permitted eventual completion of a fully subtype B RG system, and proved that all subtype-specific components could be freely exchanged between A and B systems.
BrownP. A., LupiniC., CatelliE., ClubbeJ., RicchizziE., NaylorC. J.2011; A single polymerase (L) mutation in avian metapneumovirus increased virulence and partially maintained virus viability at an elevated temperature. J Gen Virol 92:346–354 [View Article][PubMed]
BrownP. A., BriandF. X., GuionieO., LemaitreE., CourtillonC., HenryA., JestinV., EterradossiN.2013; An alternative method to determine the 5′ extremities of non-segmented, negative sense RNA viral genomes using positive replication intermediate 3′ tailing: application to two members of the Paramyxoviridae family. J Virol Methods 193:121–127 [View Article][PubMed]
BrownP. A., LemaitreE., BriandF. X., CourtillonC., GuionieO., AlléeC., ToquinD., Bayon-AuboyerM. H., JestinV., other authors. 2014; Molecular comparisons of full length metapneumovirus (MPV) genomes, including newly determined French AMPV-C and -D isolates, further supports possible subclassification within the MPV genus. PLoS One 9:e102740 [View Article]
CecchinatoM., CatelliE., LupiniC., RicchizziE., ClubbeJ., BattilaniM., NaylorC. J.2010; Avian metapneumovirus (AMPV) attachment protein involvement in probable virus evolution concurrent with mass live vaccine introduction. Vet Microbiol 146:24–34 [View Article][PubMed]
CecchinatoM., CatelliE., LupiniC., RicchizziE., ProsperiS., NaylorC. J.2014; Reversion to virulence of a subtype B avian metapneumovirus vaccine: Is it time for regulators to require availability of vaccine progenitors?. Vaccine 32:4660–4664 [View Article][PubMed]
CookJ. K., JonesB. V., EllisM. M., JingL., CavanaghD.1993; Antigenic differentiation of strains of turkey rhinotracheitis virus using monoclonal antibodies. Avian Pathol 22:257–273 [View Article][PubMed]
FalchieriM., CecchinatoM., NaylorC. J.2012; Unexpected pattern in expression of AMPV proteins: possible explanations and implications. In 7th International Symposium on Avian Corona and Avian Pneumoviruses325 Edited by Heffels-RedmannU., LutzM., KaletaE., HeckmannJ. University of Giessen: Germany: Druckerei Schroeder;
JacobsJ. A., NjengaM. K., AlvarezR., MawdittK., BrittonP., CavanaghD., SealB. S.2003; Subtype B avian metapneumovirus resembles subtype A more closely than subtype C or human metapneumovirus with respect to the phosphoprotein, and second matrix and small hydrophobic proteins. Virus Res 92:171–178[PubMed]
JonesR. C., Baxter-JonesC., WildingG. P., KellyD. F.1986; Demonstration of a candidate virus for turkey rhinotracheitis in experimentally inoculated turkeys. Vet Rec 119:599–600[PubMed]
JonesR. C., NaylorC. J., BradburyJ. M., SavageC. E., WorthingtonK., WilliamsR. A.1991; Isolation of a turkey rhinotracheitis-like virus from broiler breeder chickens in England. Vet Rec 129:509–510[PubMed]
LingR., SinkovicS., ToquinD., GuionieO., EterradossiN., EastonA. J.2008; Deletion of the SH gene from avian metapneumovirus has a greater impact on virus production and immunogenicity in turkeys than deletion of the G gene or M2-2 open reading frame. J Gen Virol 89:525–533 [View Article][PubMed]
NaylorC. J., BrownP. A., EdworthyN., LingR., JonesR. C., SavageC. E., EastonA. J.2004; Development of a reverse-genetics system for Avian pneumovirus demonstrates that the small hydrophobic (SH) and attachment (G) genes are not essential for virus viability. J Gen Virol 85:3219–3227 [View Article][PubMed]
NaylorC. J., LingR., EdworthyN., SavageC. E., EastonA. J.2007; Avian metapneumovirus SH gene end and G protein mutations influence the level of protection of live-vaccine candidates. J Gen Virol 88:1767–1775 [View Article][PubMed]
NaylorC. J., LupiniC., BrownP. A.2010; Charged amino acids in the AMPV fusion protein have more influence on induced protection than deletion of the SH or G genes. Vaccine 28:6800–6807 [View Article][PubMed]
Van de ZandeS., NauwynckH., NaylorC., PensaertM.2000; Duration of cross-protection between subtypes A and B avian pneumovirus in turkeys. Vet Rec 147:132–134[PubMed]