|Wetterer, James - Wilkes Honors College|
|Lapolla, John - Towson University|
|Firth, Andrew - Cambridge University|
Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2016
Publication Date: 6/30/2016
Citation: Valles, S.M., Oi, D.H., Becnel, J.J., Wetterer, J.K., Lapolla, J.S., Firth, A.E. 2016. Isolation and characterization of Nylanderia fulva virus 1, a positive-sense, single-stranded RNA virus infecting the tawny crazy ant, Nylanderia fulva. Virology. 496:244-254.
Interpretive Summary: The exotic and invasive Tawny crazy ant, also known as the Caribbean crazy ant, Rasberry crazy ant, or the hairy crazy ant, inundates structures, landscapes, and natural areas. Their sheer numbers result in incessant complaints, electrical malfunctions, and crop damage from tending of aphids and mealybug pests to causing pollinator honeybees to vacate hives. They are well established in Florida and Texas, and are spreading to other southern states. Effective methods to reduce populations and mitigate their spread are urgently needed. Scientists at the USDA-ARS Center for Medical, Agricultural, and Veterinary Entomology, Florida Atlantic University, Towson University, and University of Cambridge have discovered the first virus known to infect the Tawny crazy ant. These scientists have characterized the virus and sequenced its genome. The virus, NfV-1, is only the second pathogen described from the Tawny ant and may be suitable as a natural control agent for these ants.
Technical Abstract: We report the discovery of a new virus from the tawny crazy ant, Nylanderia fulva. Nylanderia fulva virus 1 (NfV-1) represents the first virus identified and characterized from this ant species. The NfV-1 genome is 10,881 nucleotides in length, excluding the poly(A) tail present on the 3' end (GenBank accession KX024775). Analysis of the genome sequence revealed one large open reading frame (ORF) yielding a predicted polyprotein of 407,455 Daltons. Helicase, protease, RNA-dependent RNA polymerase, and jelly-roll capsid protein domains were recognized within the polyprotein. Phylogenetic analysis placed NfV-1 in an unclassified clade of viruses and we suggest new sister families Solinviviridae (Solenopsis invicta virus 3 as the type species, NfV-1, and relatives) and Acypiviridae (Acyrthosiphon pisum virus as the type species, Thika virus, and relatives) to classify arthropod-infecting positive-sense RNA viruses with a calicivirus-like genome organization. Electron microscopic examination of negatively stained samples of purified preparations from NfV-1-infected colonies of tawny crazy ants revealed particles with icosahedral symmetry with a diameter of 28.7 ±1.1 nm. The virus was detected by RT-PCR in larval, pupal, worker and queen developmental stages. However, the replicative strand of NfV-1was only detected in larvae. Vertical transmission did not appear to occur as virus was not detected in eggs. However, horizontal transmission was facile. The inter-colonial field prevalence of NfV-1 was 52 ±35% with some local infections reaching 100%. NfV-1 was not detected in limited samples of other Nylanderia species or closely related ant species. The possibility of using NfV-1 as a control agent for tawny crazy ants is discussed.