title: Adipokinetic hormone activities in insect body infected by entomopathogenic nematode.
abstract: The role of adipokinetic hormone (AKH) in the firebug Pyrrhocoris apterus adults infected by the entomopathogenic nematode (EPN) Steinernema carpocapsae was examined in this study. It was found that co-application of EPN and AKH enhanced firebug mortality about 2.5 times within 24h (from 20 to 51% in EPN vs. EPN+AKH treatments), and resulted in metabolism intensification, as carbon dioxide production in firebugs increased about 2.1 and 1.6times compared to control- and EPN-treated insects, respectively. Accordingly, firebugs with reduced expression of AKH receptors showed a significantly lower mortality (by 1.6 to 2.9-folds), and lower general metabolism after EPN+AKH treatments. In addition, EPN application increased Akh gene expression in the corpora cardiaca (1.6times), AKH level in the corpora cardiaca (1.3times) and haemolymph (1.7times), and lipid and carbohydrate amounts in the haemolymph. Thus, the outcomes of the present study demonstrate involvement of AKH into the anti-stress reaction elicited by the nematobacterial infection. The exact mechanism by which AKH acts is unknown, but results suggested that the increase of metabolism and nutrient amounts in haemolymph might play a role.
authors.affiliation: Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Agriculture, University of Cairo, Giza, Egypt.
authors.forename: Emad
authors.initials: E
authors.lastname: Ibrahim
authors.affiliation: Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: Markéta
authors.initials: M
authors.lastname: Hejníková
authors.affiliation: Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: Haq Abdul
authors.initials: HA
authors.lastname: Shaik
authors.affiliation: Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Doležel
authors.affiliation: Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic. Electronic address: kodrik@entu.cas.cz.
authors.forename: Dalibor
authors.initials: D
authors.lastname: Kodrík
mesh_terms: D000818:Animals; D003335:Corpora Allata / Q000378:metabolism; D006458:Hemolymph / Q000378:metabolism; D020062:Heteroptera / Q000378:metabolism* / Q000469:parasitology*; D007301:Insect Hormones / Q000378:metabolism*; D008297:Male; D009842:Oligopeptides / Q000378:metabolism*; D009928:Organ Specificity; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D017168:Rhabditida / Q000502:physiology*
chemical_list: D007301:Insect Hormones; D009842:Oligopeptides; C044833:adipokinetic hormone; D011761:Pyrrolidonecarboxylic Acid
keywords: AKH receptor; Akh gene expression; Metabolism; Mortality; Pyrrhocoris apterus; RNAi