Natural annual cycle of heat shock protein expression in land snails: desertversusMediterranean species ofSphincterochila

Abstract

SUMMARYLand snails are subject to daily and seasonal variations in temperature and in water availability, and have evolved annual cycles of activity and aestivation as part of their survival strategy. We tested in the field whether adaptation to different habitats affects the endogenous levels of heat shock proteins (HSPs) in two closely related Sphincterochila snail species, a desiccation-resistant desert species, Sphincterochila zonata, and a Mediterranean-type, desiccation-sensitive species, S. cariosa. We examined HSP levels in various tissues of snails during aestivation and after resumption of activity. Our study shows that, during aestivation, S. cariosa had higher standing stocks of Hsp70 in the foot and the hepatopancreas, and of small HSPs (sHSPs) in all the examined tissues, whereas S. zonata had higher stocks of Hsp70 in the kidney and of Hsp90 in the kidney and in the hepatopancreas. Arousal induced a general upregulation of HSPs, except for Hsp90, the expression of which in the foot was higher during aestivation. We suggest that the stress protein machinery is upregulated during arousal in anticipation of possible oxidative stress ensuing from the accelerating metabolic rate and the exit from the deep hypometabolic state. Our findings support the concept that, in land snails, aestivation and activity represent two distinct physiological states, and suggest that land snails use HSPs as important components of the aestivation mechanism, and as part of their survival strategy during and after arousal. Our study also indicates that adaptation to different habitats results in the development of distinct strategies of HSP expression with likely consequences for the ecology and distribution of land snails. Supplementary material available online at

Solar radiation stress in climbing snails: behavioural and intrinsic features define the Hsp70 level in natural populations of Xeropicta derbentina (Pulmonata)

“…Currently, such a computer model is envisaged to be built up in our group. Whether the difference in Hsp70 expression in different body tissues, which has been reported for mollusks (Lyons et al 2003;Mizrahi et al 2009;Arad et al 2010), plays a role in this context, can therefore be addressed in the future.…”

“…Stress protein expression in snails of the superfamily Helicoidea from hot climates has been characterized recently (Mizrahi et al 2009;Arad et al 2010). This gastropod superfamily occurs in large abundance in the Mediterranean and comprises a number of morphologically very similar species.…”

Antioxidant and molecular chaperone defenses during estivation and arousal in the South American apple-snailPomacea canaliculata

“…Hsp70 expression in embryonic or juvenile material is also known for these two species (Ittiprasert et al, 2009;Sun et al, 2010). The regulation of the expression of Hsp70 and Hsp90 in intertidal and terrestrial gastropods is linked to a variety of factors at the developmental, ecological and molecular levels (Tomanek and Somero, 2002;Gunter and Degnan, 2008;Reuner et al, 2008;Ramnanan et al, 2009;Arad et al, 2010;Mizrahi et al, 2010) but no parallel studies have been made in freshwater gastropods. In the current paper, Hsc70 and Hsp70 levels in the kidney of P. canaliculata showed no significant variations throughout the activity-estivation cycle.…”

Heat shock proteins and hypometabolism: adaptive strategy for proteome preservation

“…Arousal from estivation further elevated HSPs in tissues (except for Hsp90 in the foot) indicating a need for chaperone action in rescuing protein function during arousal. 44 …”