Exploring the molecular (coping) mechanisms utilized by copepods to combat a stressful marine world


Thursday, April 5, 2012
Redfield Auditorium - 12:00 Noon
Ms. Amalia Aruda
Ph.D. Candidate, Joint Program in Biological Oceanography

The ecological success of the dominant large copepod in the North Atlantic, Calanus finmarchicus, is facilitated by its ability to enter a diapause (i.e., dormant) state. Despite the ecological significance of diapause, surprisingly little is understood about the internal mechanisms that regulate this adaptive response in calanoid copepods. Heat shock proteins (Hsps) are a superfamily of molecular chaperones, which often are upregulated during diapause and in response to stress in arthropods. To gain insight into the role of Hsps in C. finmarchicus, we cloned 8 Hsps and examined their expression in relation to the diapause state and in response to handling stress. We found that of several small Hsps that are upregulated during diapauses in the brine shrimp Artemia franciscana, only Hsp22 is also upregulated during diapause in C. finmarchicus. This difference suggests that the extent of Hsp involvement in diapause may be correlated with the relative intensity of the diapause state. I will also discuss my current thesis work that explores the molecular and physiological response of copepods to bacterial associations. Although it is known that copepod bodies are “hotspots” of bacterial activity, we lack a mechanistic understanding of how copepods interact with their microbial flora. By characterizing the physiological response of copepods to different bacterial species, we can gain insight into the dynamic influence of copepod hosts on their microflora.