Metabolic and Proteomic Profiling of Diapause in the Aphid Parasitoid Praon volucre

Abstract

BackgroundDiapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and biochemical modifications underlying diapause in non-model organisms.Methodology/Principal FindingsIn this study we focused on the parasitic wasp, Praon volucre that exhibits a pupal diapause in response to environmental signals. System-wide metabolic changes occurring during diapause were investigated using GC-MS metabolic fingerprinting. Moreover, proteomic changes were studied in diapausing versus non-diapausing phenotypes using a combination of two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry. We found a reduction of Krebs cycle intermediates which most likely resulted from the metabolic depression. Glycolysis was galvanized, probably to favor polyols biosynthesis. Diapausing parasitoids accumulated high levels of cryoprotective polyols, especially sorbitol. A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes.Conclusions/SignificanceThe results presented here provide some first clues about the molecular and biochemical events that characterize the diapause syndrome in aphid parasitoids. These data are useful for probing potential commonality of parasitoids diapause with other taxa and they will help creating a general understanding of diapause underpinnings and a background for future interpretations.

Thermal tolerance breadths among groundwater crustaceans living in a thermally constant environment

“…Glycerol, the most commonly known polyol that is accumulated in cold-acclimated insects (Koštál et al, 2007;Lalouette et al, 2007), also decreased when acclimation temperature was cooled down to 4°C. These metabolic changes in the 4°C-exposed crustaceans were indicative of an alteration of the energetic metabolism, as already evidenced in some cold-acclimated insects (Colinet et al, 2012;Foray et al, 2013). The variations of intermediary compounds of the tricarboxylic acid cycle, which represent useful biomarkers of physiological adjustments in coldexposed arthropods (Michaud et al, 2008;Foray et al, 2013), together with the activity of the ATP-dependent sodium-potassium ion pump, should be examined in further studies to precisely document this cold-induced metabolic alteration.…”

Metabolomic Analysis of Diapausing and Noni-diapausing Larvae of the European Corn Borer Ostrinia nubilalis (Hbn.) (Lepidoptera: Crambidae)

“…[19][20][21][22][23][24][25] The present study descibes application of NMR-based metabolomics to characterise molecular and biochemical changes underlying diapause in the European corn borer Ostrinia nubilalis. We compared metabolomic profiles in polar hemolymph extracts of diapausing and non-diapausing larvae of O. nubilalis using high-resolution 1H-NMR spectroscopy, and show that diapause, as a special state of physiological dormancy, has a different metabolomic fingerprint compared to active non-diapausing phase.…”

“…Since comprehensive analysis of the metabolites present in an organism or cell is crucial to understanding cellular processes and function, reports describing metabolomic approaches for studying insect biochemistry have been gradually increasing over the past several years. [19][20][21][22][23][24][25] Metabolomics as a part of systems biology can reveal the unique fingerprint of low molecular weight metabolites within a biological sample that are characteristic for a specific physiological state. 26,27 In the present study, we analyzed metabolomic profiles in diapausing larvae of the European corn borer Ostrinia nubilalis (Lepidoptera: Crambidae), a maize pest species of Eurasia and North America.…”

Transcriptional profiling of overwintering gene expression in the small carpenter bee, Ceratina calcarata

“…Despite these gross similarities, our quantitative bee-fly comparisons of coldrelated gene expression patterns (on both the transcript and GO levels) did not uncover significant overlaps. This may be attributable to speciesspecific molecular responses to cold, as suggested by a recent comparative study that also reported a lack of conserved gene expression related to dormancy between C. elegans , D. melanogaster , and S. crassipalpis (Ragland et al 2010;Colinet et al 2012). Alternatively, the lack of conservation may be explained by the fact that these studies examined different life stages and tissues (Table S5).…”

“…We characterize gene expression profiles of field-collected overwintering C. calcarata and contrast these against previously published active season gene expression profiles in the same species (Rehan et al 2014). Based on existing overwintering gene expression literature (Colinet et al 2007(Colinet et al , 2012Dunning et al 2013Dunning et al , 2014Lee et al 1998;Purac et al 2008;Ragland et al 2010;Rinehart et al 2007Rinehart et al , 2010Robich et al 2007;Torson et al 2015;Qin et al 2005;Yocum et al 2005Yocum et al , 2015, we predict that differential expression would be found in genes relating to heat shock proteins, membrane lipids, cuticular proteins, and cytoskeletal and muscular alterations. We also provide comparisons of our results to previous studies on overwintering gene expression and cold tolerance in other insects, in order to assess whether similar or different genes and pathways are associated with overwintering across taxa.…”