PARENT SESSION
TA1 - Multiple Stressors
Chair: Norton, Sue1, 1 U.S. Environmental Protection Agency, Washington, DC
8:00 AM to 12:00 PM - Tuesday, 19 November 2002
Room Ballroom G-I
(332) Investigating the Interplay Between Energetics and Immune Function in the Pathological Development of Withering Syndrome in Red Abalone (Haliotis rufescens).
Rosenblum, Eric*,1, Viant, Mark1, Tjeerdema, Ron1, Friedman, Carolyn4, Braid, Beverly5, Moore, James6, 1 University of California, Davis, Ca4 University of Washington, Seattle, Washington5 University of California, Bodega Bay Marine Lab, Bodega, Ca6 Department of Fish and Game, Bodega Bay, Ca
ABSTRACT- Withering syndrome, a fatal disease caused by a Rickettsiales-like prokaryote, has lead to a significant decline in both red and black abalone populations in California. The symptoms of the disease are the result of morphological changes in the digestive gland causing loss of function and physiological starvation. Cells once capable of secreting digestive enzymes are replaced with transport/absorptive epithelia, the result being the depletion of glycogen reserves and the use of the foot muscle protein as an energy source. It has been hypothesized that development of pathogenesis is influenced by external stressors leading to varied time courses in the progression of withering symptoms. We propose to investigate how conditions such as food availability, elevated water temperature, and exogenous chemical exposures may compromise immune function allowing the development of withering syndrome. The aims of the project are designed to elucidate relationships between environmental stressors and energy stores in abalone. Preliminary data indicates that glycogen appears to be the most robust indicator of the presence or absence of WS in both foot muscle and digestive gland however, adenylates and phosphoarginine levels can also indicate the presence or absence of WS, but appear to be tissue dependent. One interesting result showed that in the digestive gland of the abalone Adenylate levels don't appear to be affected by WS infection and most surprisingly, phosphoarginine levels increase in WS infected organism. One possible explanation is that the phosphoarginine originates from the RLPs themselves. If we can increase our understanding of the underlying mechanisms that connect the immune function to available energy stores in both the red and black abalone, it may be possible to develop appropriate measures to minimize potential impact of environmental stressors, and aid in efforts to restore the once abundant abalone populations.
Key words: abalone, energetics, multiple stressors, nmr