Meeting Abstract
The California mussel (Mytilus californianus) is an ecologically important intertidal species and studies of its physiological responses to stress can predict how mussels respond to increasing temperatures. Previous studies have shown that sirtuins (NAD-dependent deacylases) may link food availability and heat acclimation to affect the mussels tolerance to acute heat stress. The mussel’s gill plays an integral role in feeding, as cilia create a current within the mussel cavity allowing food to move toward the mouth. The ciliary beat frequency can be used as a measure of the gill’s metabolic activity, so we evaluated ciliary responses of M. californianus during recovery from acute heat shock and sirtuin inhibition. Mussels were acclimated to one of two temperatures (20°C or 30°C) during low tide and two food rations (0.25% or 1.5% mussel dry weight·day-1) for 3 wk before a subset of the mussels were exposed to sirtuin inhibitors. Subsequently, all mussels were exposed to a 33°C heat shock during emersion. Ciliary activity was monitored from an excised gill section during high tide periods of the 48 h before and after inhibition and heat shock. Four gills from each group were dissected and observed under a microscope on a temperature-controlled slide. Ciliary movements were recorded at 60 fps using a high definition camera over 30 s increments to determine average beat frequency. Given the energy dependence of ciliary activity, we predict that mussels from high food acclimation groups will recover more quickly from an acute heat shock than those from the low food group and will have average beat frequencies similar to those we recorded prior to sirtuin inhibition and heat stress (funded by NSF IOS-1557500).
