Meeting Abstract
The California mussel, Mytilus californianus, will experience increased heat stress and shifts in food availability as a result of climate change. To evaluate the role of sirtuins (NAD-dependent deacylases) as a link between temperature tolerance and food availability, we conducted a study to examine the effects of food, thermal history, and sirtuin inhibition on the response of M. californianus to acute heat stress. Mussels were acclimated for 3 wk to a semidiurnal tidal cycle, circadian rhythm, and one of four combinations of maximum emersion temperature (20 or 30°C) and food availability (0.25% or 1.5% mussel dry weight•day-1). We employed a high-resolution sampling regime over 48 h during the end of the acclimation to look at how mussels responded to the various treatments. Clearance rate was measured as the relative fluorescence of the algal particles within a static chamber, spanning 30 m of feeding. At the end of the acclimation, half of the mussels from each group were exposed to sirtuin inhibition, and then all groups were subjected to acute heat stress (33°C) during the subsequent low tide period. We then monitored recovery of the animals over the next 48 h, using clearance rate as a proxy. We predict that mussels previously acclimated to a lower temperature will decrease food intake after experiencing acute heat stress in comparison to those acclimated to a higher temperature. This effect will be more pronounced in the low food treatments. We also predict that sirtuin inhibition will further reduce feeding, as the mussels struggle to recover from acute heat stress (funded by NSF IOS-1557500).
