Production of epicormic buds by Douglas-fir in central British Columbia, Canada, following defoliation by western spruce budworm (Lepidoptera: Tortricidae)

None

Evaluation of two repellent semiochemicals for disruption of attack by the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae)

When released from attractant-baited multiple-funnel traps, 3-methyl-2-cyclohexen-1- one (MCH) reduced catches of male and female mountain pine beetles, Dendroctonus ponderosae Hopkins, by 67.4% and 71.8%, respectively. 2-Phenyl ethanol reduced the respective catches by 96.6% and 95.1%, but only verbenone and all three compounds together reduced catches to levels no different from those in unbaited control traps. In another experiment, all three binary combinations of the above compounds, plus the ternary combination, reduced catches of both sexes by >96%. In comparable tree protection experiments near Princeton BC, MCH and 2-phenyl ethanol alone and together significantly reduced the percentages of pheromone-baited lodgepole pines that were attacked by 16.0%, 33.3% and 40.0%, respectively, but verbenone alone totally protected baited trees, and many trees within 5 m of them, from attack. In identical experiments near Prince George BC, where mountain pine beetle populations were much higher, adding MCH, 2-phenyl ethanol or both together to verbenone did not cause attack to be reduced significantly beyond that achieved by verbenone alone. Our results confirm that 2-phenyl ethanol is an antiaggregation pheromone for the mountain pine beetle, and that MCH is an interspecific synomone. However, because neither was as effective as verbenone in protecting pheromone-baited trees from attack, and adding either or both to verbenone did not improve protection, neither compound warrants further consideration as a potential tool for operational disruption of attack

F.A.R.O.G. FORUM, Vol. 5 No. 7

https://digitalcommons.library.umaine.edu/francoamericain_forum/1019/thumbnail.jp

Active Site Mutations Change the Cleavage Specificity of Neprilysin

Neprilysin (NEP), a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe563 and Ser546. Among the mutants studied in detail we observed changes in their activity towards leucine5-enkephalin, insulin B chain, and amyloid β1–40. For example, NEPF563I displayed an increase in preference towards cleaving leucine5-enkephalin relative to insulin B chain, while mutant NEPS546E was less discriminating than neprilysin. Mutants NEPF563L and NEPS546E exhibit different cleavage site preferences than neprilysin with insulin B chain and amyloid ß1–40 as substrates. These data indicate that it is possible to alter the cleavage site specificity of neprilysin opening the way for the development of substrate specific or substrate exclusive forms of the enzyme with enhanced therapeutic potential

Rapid Effects of Hearing Song on Catecholaminergic Activity in the Songbird Auditory Pathway

Catecholaminergic (CA) neurons innervate sensory areas and affect the processing of sensory signals. For example, in birds, CA fibers innervate the auditory pathway at each level, including the midbrain, thalamus, and forebrain. We have shown previously that in female European starlings, CA activity in the auditory forebrain can be enhanced by exposure to attractive male song for one week. It is not known, however, whether hearing song can initiate that activity more rapidly. Here, we exposed estrogen-primed, female white-throated sparrows to conspecific male song and looked for evidence of rapid synthesis of catecholamines in auditory areas. In one hemisphere of the brain, we used immunohistochemistry to detect the phosphorylation of tyrosine hydroxylase (TH), a rate-limiting enzyme in the CA synthetic pathway. We found that immunoreactivity for TH phosphorylated at serine 40 increased dramatically in the auditory forebrain, but not the auditory thalamus and midbrain, after 15 min of song exposure. In the other hemisphere, we used high pressure liquid chromatography to measure catecholamines and their metabolites. We found that two dopamine metabolites, dihydroxyphenylacetic acid and homovanillic acid, increased in the auditory forebrain but not the auditory midbrain after 30 min of exposure to conspecific song. Our results are consistent with the hypothesis that exposure to a behaviorally relevant auditory stimulus rapidly induces CA activity, which may play a role in auditory responses

2017 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1004/thumbnail.jp