SSH library
Expressed sequence tags (ETSs) are sequences of fragments of expressed genes (mRNA). These sequences can be aligned with non-redundant databases like GenBank to get information about their annotations and functions. Three libraries have been established in cooperation with EcoArray Inc in Florida, USA. By the use of suppression subtractive hybridization (SSH) PCR methodology, we have been able to focus on genes induced by relatively specific contaminants like oil compounds, heavy metals and amines. The overall aim of this approach is to establish analytical tools to specify which biological systems in C. finmarchicus that is affected by specific contaminants.

We have so far established three Calanus finmarchicus EST libraries, consisting of nearly 3000 ESTs. These have been BLASTed, and we have discovered unique sequences. After BLAST alignments towards crustacean genomic sequences in GenBank we have found highly similar matches, and of these we have now clones of ESTs from some very interesting genes in a toxicological sense. Some of these are listed below:

  • Antioxidants: Glutathione peroxidase, thioredoxin reductase.
  • Protein degradation: Proteasome 26S, ubiquitin, beclin-1 like protein.
  • Energy metabolism: ATP synthase, ubiquinol cytochrome c reductase, cytochrome c1, cytochrome b, glyceraldehyd-3 phosphate dehydrogenase.
  • Fatty acid metabolism: Phospholipid-transporting ATPase, intracellular fatty acid binding protein.
  • Xenobiotic biotransformation: CYP2L1, CYP330, CYP2K.
  • Heat shock proteins: HSP24, HSP-70, HSP-90.
  • Transporters: Amine transporter.
  • Enzyme catalysis: Amine oxidase, succinate dehydrogenase.
  • Housekeeping genes: Elongation factors 1A and 2, beta-tubulin, afa-tubulin, actin

We are continuously uploading ESTs to NCBI GenBank, and the complete list is found under "Submission to GenBank".

We are continuously working to develop real-time PCR-methods to to quantify the expression of specific mRNAs during exposure to different types of stressors (oil compounds, heavy metals, amines, elevated temperature and more).

Published March 31, 2007

Calanus finmarchicus - a new and relevant test species for assessing effects of toxicants and climate changes in the marine environment.