Behavioral, metabolic, and molecular stress responses of marine bivalve Mytilus galloprovincialis during long-term acclimation at increasing ambient temperature

Abstract

The present study aimed to determine the thermal response of the Mediterranean mussel Mytilus galloprovincialis by integrating information from various levels of biological organization including behavior, metabolic adjustments, heat shock protein expression, and protein kinase activity. Behavioral responses were determined by examining the effect of warming on valve closure and opening. Metabolic impacts were assessed by examining the activity of the key glycolytic enzyme pyruvate kinase (PK). Molecular responses were addressed through the expression of Hsp70 and Hsp90 and the phosphorylation of stress-activated protein kinases, p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs). Mussels increased the duration of valve closure by about sixfold when acclimated to 24 degrees C rather than to 17 degrees C. As indicated by the activity of PK, such behavior caused metabolic depression and probably a shift from aerobic to anaerobic metabolism. Acclimation to temperatures higher than 24 degrees C caused an increase in mortality and induced the expression of Hsp72. Increased phosphorylation of p38 MAPK and JNKs indicated activation of MAPK signaling cascades. The potential involvement of MAPKs in the induction of Hsp genes in the tissues of M. galloprovincialis is discussed. In conclusion, it seems that M. galloprovincialis lives close to its acclimation limits and incipient lethal temperature and that a small degree of warming will elicit stress responses at whole organism and molecular levels.

Metallothionein and glutathione inLymnaea stagnalisdetermine the specificity of responses to the effects of ionising radiation

“…An increase in anaerobic glycolysis is a well-known sign of toxic effect in molluscs (Anestis et al, 2007). In our study, despite the favourable regime of respiration, laboratory groups had comparatively high LDH activity that attests to the shift to anaerobiosis.…”

Comparative physiological, biochemical, and molecular thermal stress response profiles for two Unionid freshwater mussel species

“…It is well documented that upper thermal tolerance limits induce physiological and behavioral modifications that initially lead to higher metabolic rates due to increased oxygen demand (Braby and Somero, 2006;Klepsatel et al, 2013). However, maintaining these high metabolic rates is costly and energetic reserves required for aerobic respiration are eventually depleted (Axenov-Gribanov et al, 2014;Grieshaber et al, 1994), leading to metabolic depression and a shift from aerobic to anaerobic respiration (Anestis et al, 2007(Anestis et al, , 2008Sokolova et al, 2012). This could explain the absence of glycogen accumulation, a critical energy reserve for bivalves, and subsequent decrease in growth rates during the recovery period.…”

Thermal stress increases fluctuating asymmetry in marine mussels: environmental variation and developmental instability

“…For instance, changes in temperature have been linked to ecological shifts in species distribution (Jones et al 2009, Sorte et al 2010, Poloczanska et al 2013, feeding/foraging behavior (Sanford 1999, Yamane and Gilman 2009, Nishizaki and Carrington 2014a, Hayford et al 2015, biomaterial production/performance (O'Donnell et al 2013), and seasonal phenology of reproductive activity (Poloczanska et al 2013, Philippart et al 2014, Neeman et al 2015. Thermal conditions also affect physiological function as measured through changes in respiration (Pö rtner 2002, Nishizaki andCarrington 2014b), heart rate (DeFur and Mangum 1979, Marshall et al 2011), photosynthesis (Colvard et al 2014), growth (Nishizaki and Carrington, in press), Hsp expression (Hamdoun et al 2003, Todgham et al 2006, Gracey et al 2008, protein abundance (Tomanek and Zuzow 2010) and phosphorylation of stress-activated protein kinases (Anestis et al 2007). However, the efficacy of these varied responses is often rooted in an organism's ability to fulfill precise developmental patterns (Burggren and Warburton 2005).…”