title: Critical role for protein kinase A in the acquisition of gregarious behavior in the desert locust.
abstract: The mechanisms that integrate genetic and environmental information to coordinate the expression of complex phenotypes are little understood. We investigated the role of two protein kinases (PKs) in the population density-dependent transition to gregarious behavior that underlies swarm formation in desert locusts: the foraging gene product, a cGMP-dependent PK (PKG) implicated in switching between alternative group-related behaviors in several animal species; and cAMP-dependent PK (PKA), a signal transduction protein with a preeminent role in different forms of learning. Solitarious locusts acquire key behavioral characters of the swarming gregarious phase within just 1 to 4 h of forced crowding. Injecting the PKA inhibitor KT5720 before crowding prevented this transition, whereas injecting KT5823, an inhibitor of PKG, did not. Neither drug altered the behavior of long-term gregarious locusts. RNAi against foraging effectively reduced its expression in the central nervous system, but this did not prevent gregarization upon crowding. By contrast, solitarious locusts with an RNAi-induced reduction in PKA catalytic subunit C1 expression behaved less gregariously after crowding, and RNAi against the inhibitory R1 subunit promoted more extensive gregarization following a brief crowding period. A central role of PKA is congruent with the recent discovery that serotonin mediates gregarization in locusts and with findings in vertebrates that similarly implicate PKA in the capacity to cope with adverse life events. Our results show that PKA has been coopted into effecting the wide-ranging transformation from solitarious to gregarious behavior, with PKA-mediated behavioral plasticity resulting in an environmentally driven reorganization of a complex phenotype.
authors.affiliation: Department of Zoology,  University of Cambridge, Cambridge CB2 3EJ,  United Kingdom.
authors.forename: Swidbert R
authors.initials: SR
authors.lastname: Ott
authors.forename: Heleen
authors.initials: H
authors.lastname: Verlinden
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Rogers
authors.forename: Caroline H
authors.initials: CH
authors.lastname: Brighton
authors.forename: Pei Shan
authors.initials: PS
authors.lastname: Quah
authors.forename: Rut K
authors.initials: RK
authors.lastname: Vleugels
authors.forename: Rik
authors.initials: R
authors.lastname: Verdonck
authors.forename: Jozef
authors.initials: J
authors.lastname: Vanden Broeck
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002227:Carbazoles / Q000494:pharmacology; D020134:Catalytic Domain; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D006110:Grasshoppers / Q000502:physiology*; D008969:Molecular Sequence Data; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D034622:RNA Interference
chemical_list: D002227:Carbazoles; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; C057416:KT 5720; D017868:Cyclic AMP-Dependent Protein Kinases