title: Heritability of hsp70 expression in the beetle Tenebrio molitor: Ontogenetic and environmental effects.
abstract: Ectotherms constitute the vast majority of terrestrial biodiversity and are especially likely to be vulnerable to climate warming because their basic physiological functions such as locomotion, growth, and reproduction are strongly influenced by environmental temperature. An integrated view about the effects of global warming will be reached not just establishing how the increase in mean temperature impacts the natural populations but also establishing the effects of the increase in temperature variance. One of the molecular responses that are activated in a cell under a temperature stress is the heat shock protein response (HSP). Some studies that have detected consistent differences among thermal treatments and ontogenetic stages in HSP70 expression have assumed that these differences had a genetic basis and consequently expression would be heritable. We tested for changes in quantitative genetic parameters of HSP70 expression in a half-sib design where individuals of the beetle Tenebrio molitor were maintained in constant and varying thermal environments. We estimated heritability of HSP70 expression using a linear mixed modelling approach in different ontogenetic stages. Expression levels of HSP70 were consistently higher in the variable environment and heritability estimates were low to moderate. The results imply that within each ontogenetic stage additive genetic variance was higher in the variable environment and in adults compared with constant environment and larvae stage, respectively. We found that almost all the genetic correlations across ontogenetic stages and environment were positive. These suggest that directional selection for higher levels of expression in one environment will result in higher expression levels of HSP70 on the other environment for the same ontogenetic stage.
authors: Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibañez, Santiago, Chile; Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibañez, Diagonal Las Torres 2640, Peñalolen, Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), Chile. Electronic address: marco.lardies@uai.cl.
authors: Marco A
authors: MA
authors: Lardies
authors: Natural History Museum, Imperial College of London, United Kingdom.
authors: María Belén
authors: MB
authors: Arias
authors: Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibañez, Diagonal Las Torres 2640, Peñalolen, Santiago, Chile.
authors: María Josefina
authors: MJ
authors: Poupin
authors: Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
authors: Leonardo D
authors: LD
authors: Bacigalupe
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology*; D014644:Genetic Variation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007814:Larva / Q000235:genetics* / Q000254:growth & development*; D008018:Life Cycle Stages; D013696:Temperature; D013712:Tenebrio / Q000235:genetics* / Q000254:growth & development*
chemical_list: D018840:HSP70 Heat-Shock Proteins
keywords: Animal model; Climate change; Half-sib design; Tenebrio molitor; Thermal adaptation; Thermotolerance