Differential gene expression during the moult cycle of Antarctic krill (Euphausia superba)

Paul J Seear, Geraint A Tarling, Gavin Burns, William P Goodall-Copestake, Edward Gaten, Özge Özkaya, Ezio Rosato

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Background
All crustaceans periodically moult to renew their exoskeleton. In krill this involves partial digestion and resorption of the old exoskeleton and synthesis of new cuticle. Molecular events that underlie the moult cycle are poorly understood in calcifying crustaceans and even less so in non-calcifying organisms such as krill. To address this we constructed an Antarctic krill cDNA microarray in order to generate gene expression profiles across the moult cycle and identify possible activation pathways.

Results
A total of 26 different cuticle genes were identified that showed differential gene expression across the moult cycle. Almost all cuticle genes were up regulated during premoult and down regulated during late intermoult. There were a number of transcripts with significant sequence homology to genes potentially involved in the synthesis, breakdown and resorption of chitin. During early premoult glutamine synthetase, a gene involved in generating an amino acid used in the synthesis of glucosamine, a constituent of chitin, was up regulated more than twofold. Mannosyltransferase 1, a member of the glycosyltransferase family of enzymes that includes chitin synthase was also up regulated during early premoult. Transcripts homologous to a β-N-acetylglucosaminidase (β-NAGase) precursor were expressed at a higher level during late intermoult (prior to apolysis) than during premoult. This observation coincided with the up regulation during late intermoult, of a coatomer subunit epsilon involved in the production of vesicles that maybe used to transport the β-NAGase precursors into the exuvial cleft. Trypsin, known to activate the β-NAGase precursor, was up regulated more than fourfold during premoult. The up regulation of a predicted oligopeptide transporter during premoult may allow the transport of chitin breakdown products across the newly synthesised epi- and exocuticle layers.

Conclusion
We have identified many genes differentially expressed across the moult cycle of krill that correspond with known phenotypic structural changes. This study has provided a better understanding of the processes involved in krill moulting and how they may be controlled at the gene expression level.
Original languageEnglish
Number of pages13
JournalBMC Genomics
Volume11
Issue number1
Early online date19 Oct 2010
DOIs
Publication statusE-pub ahead of print - 19 Oct 2010

Keywords

  • Chitin
  • Antarctic Krill
  • Moult Cycle
  • Moult Stage
  • Euphausia Superba

Fingerprint Dive into the research topics of 'Differential gene expression during the moult cycle of Antarctic krill (Euphausia superba)'. Together they form a unique fingerprint.

  • Cite this