title: Proteome stability, heat hardening and heat-shock protein expression profiles inCataglyphisdesert ants.
abstract: In ectotherms, high temperatures impose physical limits, impeding activity. Exposure to high heat levels causes various deleterious and lethal effects, including protein misfolding and denaturation. Thermophilic ectotherms have evolved various ways to increase macromolecular stability and cope with elevated body temperatures; these include the high constitutive expression of molecular chaperones. In this study, we investigated the effect of moderate to severe heat shock (37-45°C) on survival, heat hardening, protein damage and the expression of five heat tolerance-related genes (hsc70-4 h1,hsc70-4 h2,hsp83,hsc70-5andhsf1)in two closely relatedCataglyphisants that occur in distinct habitats. Our results show that the highly thermophilic Sahara antCataglyphis bombycinaconstitutively expresses HSC70 at higher levels, but has lower induced expression of heat tolerance-related genes in response to heat shock, as compared with the more mesophilicCataglyphis mauritanicafound in the Atlas Mountains. As a result,C. bombycinademonstrates increased protein stability when exposed to acute heat stress but is less disposed to acquiring induced thermotolerance via heat hardening. These results provide further insight into the evolutionary plasticity of thehspgene expression system and subsequent physiological adaptations in thermophilous desert insects to adapt to harsh environmental conditions.
authors.affiliation: Evolutionary Biology and Ecology, Université Libre de Bruxelles, 1050 Brussels, Belgium Quentin.Willot@ulb.ac.be.
authors.forename: Quentin
authors.identifier: 0000-0001-5955-9456
authors.initials: Q
authors.lastname: Willot
authors.affiliation: Molecular Biology of the Gene, Université Libre de Bruxelles, 6041 Charleroi (Gosselies), Belgium.
authors.forename: Cyril
authors.initials: C
authors.lastname: Gueydan
authors.affiliation: Evolutionary Biology and Ecology, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors.forename: Serge
authors.initials: S
authors.lastname: Aron
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001000:Ants / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D020543:Proteome; D013312:Stress, Physiological
chemical_list: D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D020543:Proteome
keywords: Heat shock response; Heat stress; Molecular chaperone