Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

The marine snail, Littorina littorea, can endure oxygen deprivation for days at a time and tolerate the freezing of > 50 % of its body fluids. Both capacities support its intertidal lifestyle and adaptations of intermediary metabolism that support stress tolerance have been well studied. Nothing was known, however, about the role of gene expression in anoxia or freezing survival. To address this, we prepared cDNA libraries (using mRNA from foot muscle of stressed animals) and differentially screened them using control and stress cDNA probes. Screening of the anoxic library yielded 47 unique clones, of which 18 were confirmed as up-regulated during anoxia by northern blots. Differential screening of the library from frozen snails produced 13 clones, northern blots confirming increased transcript abundance for 4. All up-regulated clones show a polyA tail, a polyadenylation signal, a stop codon and a substantial open reading frame but > 90% were truncated, missing a 5'UTR and a start codon. To date, none of the confirmed positive clones have been identified via BLAST or FASTA alignment searches. However, five anoxia-induced clones have very similar sequences, suggesting that they may represent a novel gene family. Northern blots also revealed that all clones are unique to their particular stress which shows that anoxia and freezing up-regulate different genes.

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Poster Number PAenglish0445
Keywords: anaerobiosis, freeze tolerance, gastropod mollusc, gene expression, cDNA library