title: Parasitic Manipulation of Host Behaviour: Baculovirus SeMNPV EGT Facilitates Tree-Top Disease in Spodoptera exigua Larvae by Extending the Time to Death.
abstract: Many parasites enhance their dispersal and transmission by manipulating host behaviour. One intriguing example concerns baculoviruses that induce hyperactivity and tree-top disease (i.e., climbing to elevated positions prior to death) in their caterpillar hosts. Little is known about the underlying mechanisms of such parasite-induced behavioural changes. Here, we studied the role of the ecdysteroid UDP-glucosyltransferase (egt) gene of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) in tree-top disease in S. exigua larvae. Larvae infected with a mutant virus lacking the egt gene exhibited a shorter time to death and died before the induction of tree-top disease. Moreover, deletion of either the open reading frame or the ATG start codon of the egt gene prevented tree-top disease, indicating that the EGT protein is involved in this process. We hypothesize that SeMNPV EGT facilitates tree-top disease in S. exigua larvae by prolonging the larval time to death. Additionally, we discuss the role of egt in baculovirus-induced tree-top disease.
authors.affiliation: Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. yue.han@wur.nl.
authors.forename: Yue
authors.initials: Y
authors.lastname: Han
authors.affiliation: Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. vanhoute.stineke@gmail.com.|Centre for Ecology and Conservation, Biosciences, University of Exeter, Penryn, Cornwall TR10 9FE, UK. vanhoute.stineke@gmail.com.
authors.forename: Stineke
authors.initials: S
authors.lastname: van Houte
authors.affiliation: Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. gerben0811@gmail.com.
authors.forename: Gerben F
authors.initials: GF
authors.lastname: Drees
authors.affiliation: Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. monique.vanoers@wur.nl.
authors.forename: Monique M
authors.initials: MM
authors.lastname: van Oers
authors.affiliation: Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands. vera.ros@wur.nl.
authors.forename: Vera I D
authors.initials: VI
authors.lastname: Ros
keywords: SeMNPV; Spodoptera exigua; baculovirus; behavioural manipulation; egt gene; tree-top disease