Abstracts (first author)

Poster 

Walking with insects: molecular mechanisms behind parasitic manipulation of caterpillar behaviour

Author(s): Ros VID, Van Houte S, Van Oers MM

Summary:

Parasitic modification of host behaviour is a widely adopted strategy of parasites to enhance their own transmission. The examples of behavioural manipulation are rapidly accumulating, covering a broad spectrum of parasites and hosts. Nevertheless, surprisingly little is known on the underlying causative molecular mechanisms. A typical case of behavioural manipulation is found in insects infected with baculoviruses. Infected caterpillars show enhanced mobility and start climbing to the top of plants or the forest canopy (‘tree top disease’). As a consequence, the virus is spread over a larger area, thereby increasing the chance to infect a new caterpillar. The baculovirus-insect system provides an excellent platform to study parasitic manipulation of insect host behaviour. It allows the comparative analysis between wildtype viruses and single gene knock-out mutants. Recently, the egt gene from the baculovirus Lymantria dispar nucleopolyhedrovirus (LdMNPV) was identified to induce tree top disease in Lymantria dispar larvae. Here, we studied the effect of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) on climbing behaviour in two different host insects, the cabbage looper Trichoplusia ni and the beet armyworm Spodoptera exigua. We show that the effect of this virus on caterpillar behaviour differs between these two host species. Additionally, we found no evidence for a general role of the egt gene in causing tree top disease. This implies that baculoviruses have evolved multiple strategies to manipulate similar behavioural phenotypes in their caterpillar hosts.



Abstracts (coauthor)

Summary:

Baculoviruses are known to manipulate the behaviour of their caterpillar hosts, by inducing hyperactivity and altered climbing behaviour. To date, however, knowledge on parasitic genes governing such behavioural manipulations is scarce. Previously we have shown that the baculovirus Autographa californica nuclear polyhedrovirus (AcMNPV) induces hyperactive behaviour in Spodoptera exigua caterpillars, and that the viral protein tyrosine phosphatase (ptp) gene is a key player in the induction of hyperactivity. However, this gene is present in only a subset of phylogenetically related baculoviruses, while it is hypothesized that also baculoviruses that do not carry ptp are able to manipulate behaviour, possibly induced by a different viral gene. We compared behavioural changes in Spodoptera exigua caterpillars induced by two baculovirus species: the generalist AcMNPV (carrying ptp) and the specialist SeMNPV (not carrying ptp). We discuss the possible (difference in) mechanism that these two viruses use to manipulate behaviour in the context of host-pathogen coevolution.

Contacts

Chairman: Octávio S. Paulo
Tel: 00 351 217500614 direct
Tel: 00 351 217500000 ext22359
Fax: 00 351 217500028
email: mail@eseb2013.com

Address

XIV Congress of the European Society for Evolutionary Biology

Organization Team
Department of Animal Biology (DBA)
Faculty of Sciences of the University of Lisbon
P-1749-016 Lisbon
Portugal

Website

Computational Biology & Population Genomics Group 
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