Cold hardening processes in the Antarctic springtail, Cryptopygus antarcticus: Clues from a microarray

Abstract

The physiology of the Antarctic microarthropod, Cryptopygus antarcticus, has been well studied, particularly with regard to its ability to withstand low winter temperatures. However, the molecular mechanisms underlying this phenomenon are still poorly understood. 1180 sequences (Expressed Sequence Tags or ESTs) were generated and analyzed, from populations of C. antarcticus. This represents the first publicly available sequence data for this species. A sub-set (672 clones) were used to generate a small microarray to examine the differences in gene expression between summer acclimated cold tolerant and non-cold tolerant springtails. Although 60% of the clones showed no sequence similarity to annotated genes in the datasets, of those where putative function could be inferred via database homology, there was a clear pattern of up-regulation of structural proteins being associated with the cold tolerant group. These structural proteins mainly comprised cuticle proteins and provide support for the recent theory that summer SCP variation within Collembola species could be a consequence of moulting, with moulting populations having lowered SCPs.

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

“…15 Most studies on the molecular basis of insect cold hardiness conducted to date have been based on the level of the genome, transcriptome and proteome. [15][16][17][18] Despite significant progress in this area, many aspects of the metabolic adaptations underlying diapause and cold hardiness remain undiscovered, especially in non-model organisms. We propose that a metabolomic approach could provide insight into the metabolite composition underlying adaptations in response to unfavourable environmental conditions, such as low temperature.…”

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

“…Cuticle differentiation and reorganization is a common response to cold temperatures found in many insects (Dunning et al 2013(Dunning et al , 2014Colinet et al 2012;Purac et al 2008). Although we did not find differential gene expression in this gene family in our brain transcription assays, we did identify two cuticular protein-coding genes (cuticular protein 49AC and 60D ) that were uniquely expressed in overwintering females.…”

“…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.…”

Surviving in a frozen desert: environmental stress physiology of terrestrial Antarctic arthropods

“…In the first, animals with 'low' supercooling points (<-15°C) were compared with those with 'high' supercooling points (>-15°C), to determine which genes are responsible for lowering supercooling points (Purać et al, 2008). This microarray contained a subset of 672 expressed sequence tags (ESTs), and thus was not comprehensive.…”