‘Suicide’ of crickets harbouring hairworms: a proteomics investigation

Abstract

Despite increasing evidence of host phenotypic manipulation by parasites, the underlying mechanisms causing infected hosts to act in ways that benefit the parasite remain enigmatic in most cases. Here, we used proteomics tools to identify the biochemical alterations that occur in the head of the cricket Nemobius sylvestris when it is driven to water by the hairworm Paragordius tricuspidatus. We characterized host and parasite proteomes during the expression of the water-seeking behaviour. We found that the parasite produces molecules from the Wnt family that may act directly on the development of the central nervous system (CNS). In the head of manipulated cricket, we found differential expression of proteins specifically linked to neurogenesis, circadian rhythm and neurotransmitter activities. We also detected proteins for which the function(s) are still unknown. This proteomics study on the biochemical pathways altered by hairworms has also allowed us to tackle questions of physiological and molecular convergence in the mechanism(s) causing the alteration of orthoptera behaviour. The two hairworm species produce effective molecules acting directly on the CNS of their orthoptera hosts.

Malaria Plasmodium agent induces alteration in the head proteome of their Anopheles mosquito host

“…An investigation of parasite-induced effects on host CNS proteome expression may play a crucial role in this respect [13], especially in insect vector-pathogen systems [14]. Proteomics, with the ability to investigate the translation of genomic information, offers an approach to study the global changes in protein expression of the host CNS caused by parasites [15][16][17]. Here, we have applied such an approach to the Anopheles gambiae-Plasmodium berghei (murine malaria) experimental model to elucidate the molecular mechanisms in the brain that underlie behavioural modifications.…”

What can parasitoid wasps teach us about decision-making in insects?

“…Such proteins can then be extracted and their mass and amino acid sequence can be determined via mass spectrophotometry and aligned against available databases. Pioneer proteomics studies on manipulated hosts have been carried out on seven arthropod hostparasite associations, among which two Orthoptera-hairworm associations Biron et al, 2006;Lefevre et al, 2007). These studies have contributed to the discovery of candidate genes and of biochemical pathways altered in host CNS during the parasite manipulation for three aberrant host behaviours: suicidal behaviour, increase in probing rate and alteration of evasive behaviour.…”

Parasites: evolution’s neurobiologists

“…Proteomic and molecular studies on parasitic manipulators suggest that parasites typically target molecules not traditionally considered crucial for neural transmission (e.g. Hayakawa et al, 2000;Biron et al, 2005;Biron et al, 2006;Ponton et al, 2006;Hoover et al, 2011). For example, proteins involved in neural development appear to play a role in altering host behaviour in some systems Ponton et al, 2006), even though neural development is no longer occurring in the adult hosts.…”

“…Altering host genomic and/or proteomic function may be a common method of exerting control over host behaviour (see Biron et al, 2005;Biron et al, 2006;Biron and Loxdale, 2013). For example, a virus (baculovirus, Lymantria dispar nucleopolyhedrovirus) causes its caterpillar host to climb to an elevated position prior to death, allowing the escaping infectious viral particles to rain down on new hosts.…”