Antarctic krill 454 pyrosequencing reveals chaperone and stress transcriptome

Area of Science:

• Marine Biology
• Genomics
• Climate Change Adaptation

Background:

• Antarctic krill (Euphausia superba) is a keystone species in the Antarctic food web, vital for ecosystem balance.
• Climate change is impacting krill populations, necessitating research into their physiological functions.
• Understanding krill biology is crucial for life history, energy budget, and food web models.

Purpose of the Study:

• To generate and analyze the first 454 transcriptome data for a pelagic Antarctic crustacean.
• To identify genes related to cellular stress responses in Antarctic krill.
• To provide a genomic resource for future studies on krill physiology and adaptation.

Main Methods:

• 454 pyrosequencing was used to generate the transcriptome of Euphausia superba.
• Bioinformatic analysis identified contigs, microsatellites, and single nucleotide polymorphisms (SNPs/INDELs).
• In-depth analysis focused on cellular chaperone and antioxidant protein systems.

Main Results:

• The transcriptome assembly yielded 22,177 contigs, with identified sequences for HSP70, HSP90, and superoxide dismutase.
• Potentially novel gene duplications were discovered for key chaperone proteins.
• The dataset includes 41,470 microsatellites and 17,776 SNPs/INDELs, valuable for population genetics.

Conclusions:

• Highly expressed "stress proteins" like HSP70 and HSP90 suggest adaptation to cold environments and oxidative stress.
• These findings provide a significant resource for understanding marine ectotherm responses to environmental change.
• The data will facilitate future physiological research on krill and other Antarctic marine life.