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Author Lardies, M.A.; Arias, M.B.; Bacigalupe, L.D. pdf  doi
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  Title Phenotypic covariance matrix in life-history traits along a latitudinal gradient: a study case in a geographically widespread crab on the coast of Chile Type
  Year 2010 Publication Marine Ecology-Progress Series Abbreviated Journal Mar. Ecol.-Prog. Ser.  
  Volume 412 Issue Pages 179-187  
  Keywords Intertidal; Reproduction; Crustacea; Plasticity; Clinical variation  
  Abstract Geographically widely spread species can cope with environmental differences among habitats by genetic differentiation and/or phenotypic flexibility. In marine crustaceans, intraspecific variations in life-history traits are pervasive along latitudinal clines. Replicated latitudinal clines are of evolutionary interest because they provide evidence of the occurrence of natural selection. If the means of traits along the latitudinal gradient are expected to be the result of natural selection, there is no reason why variances and covariances will not also be subject to selection, since selection is essentially a multivariate phenomenon. We studied life-history changes in means, variances, and covariances (i.e. P matrix) in 6 populations of the endemic crab Cyclograpsus cinereus (Decapoda: Grapsidae) along a latitudinal gradient over 19 degrees on the Chilean coast. Trait means differed among localities for all traits analyzed (i.e. female size, number and size of eggs, and reproductive output), and the variation displayed a clinal pattern. In general, the main result that emerged from planned comparisons of P matrices is that, when detected, differences between localities mainly reflect differences in the magnitude of phenotypic variation (i.e. eigenvalues), rather than in the relationships between traits (i.e. eigenvectors). Sea-surface temperature was only correlated with the covariance between egg numbers and reproductive output. Matrices comparisons for Flury and jackknife methods were highly linked, with limits of biogeographic provinces described for the coast of Chile. Our study strongly highlights the importance of estimating the P matrix, not only mean values, in order to understand the evolution of life-history traits along a latitudinal gradient. Furthermore, the study of the variation in the P matrix might provide important insights into those evolutionary forces acting on it.  
  Address [Lardies, Marco A.; Belen Arias, Maria] Univ Adolfo Ibanez, Dept Ciencias, Fac Artes Liberaies, Santiago, Chile, Email: marco.lardies@uai.cl  
  Corporate Author Thesis  
  Publisher Inter-Research Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000281565900015 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 96  
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Author Arias, M.B.; Poupin, M.J.; Lardies, M.A. pdf  doi
openurl 
  Title Plasticity of life-cycle, physiological thermal traits and Hsp70 gene expression in an insect along the ontogeny: Effect of temperature variability Type
  Year 2011 Publication Journal Of Thermal Biology Abbreviated Journal J. Therm. Biol.  
  Volume 36 Issue 6 Pages 355-362  
  Keywords Chill-coma; Recovery time; Complex life-cycle; Trade-off; Thermotolerance; Development plasticity  
  Abstract It is considered that extreme environmental temperature, rather than mean temperatures exert a selective pressure in ectotherms. Consequently, it is important to understand how the predicted increase in temperature variance with a higher frequency of extreme events in climate change is likely to impact on organisms. Thermal tolerance traits (i.e. chill-coma, recovery time, Hsp70 expression) are directly linked with performance in ectotherms and have consequences in life-history traits. We examined the effects of temperature variability on thermal tolerance and life-history traits through ontogeny of an insect with a complex life-cycle: the yellow mealworm beetle Tenebrio molitor. We established two common gardens with 100 recently ovoposited eggs each. Larvae were reared from hatching to adult on either a variable (mean=18 degrees C and a variance of 6.8 degrees C) or constant (18 +/- 1 degrees C) thermal environment. Development rate and growth rate were similar between thermal environments. Results indicate that larvae reared in a variable environment are more cold-tolerant than larvae of a constant environment. Interestingly, these results are reversed in the adult stage, outlining an inter-stage physiological cost. Gene expression pattern of an Hsp70 gene was well correlated with larval thermotolerance to cold in the variable environment but higher gene expression in adults is not correlated with individual's thermotolerance. We conclude that chill-coma, recovery time and Hsp70 gene expression are plastic in response to a thermal environment but also change significantly their responses depending on the ontogenetic stage, implying that the response of adult individuals is linked to early stages of the life-cycle. (C) 2011 Elsevier Ltd. All rights reserved,  
  Address [Arias, MB; Lardies, MA] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Santiago, Chile, Email: marco.lardies@uai.cl  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 0306-4565 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000295018400009 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 168  
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Author Gaitan-Espitia, J.D.; Arias, M.B.; Lardies, M.A.; Nespolo, R.F. pdf  doi
openurl 
  Title Variation in Thermal Sensitivity and Thermal Tolerances in an Invasive Species across a Climatic Gradient: Lessons from the Land Snail Cornu aspersum Type
  Year 2013 Publication Plos One Abbreviated Journal PLoS One  
  Volume 8 Issue 8 Pages  
  Keywords  
  Abstract The ability of organisms to perform at different temperatures could be described by a continuous nonlinear reaction norm (i.e., thermal performance curve, TPC), in which the phenotypic trait value varies as a function of temperature. Almost any shift in the parameters of this performance curve could highlight the direct effect of temperature on organism fitness, providing a powerful framework for testing thermal adaptation hypotheses. Inter-and intraspecific differences in this performance curve are also reflected in thermal tolerances limits (e. g., critical and lethal limits), influencing the biogeographic patterns of species' distribution. Within this context, here we investigated the intraspecific variation in thermal sensitivities and thermal tolerances in three populations of the invasive snail Cornu aspersum across a geographical gradient, characterized by different climatic conditions. Thus, we examined population differentiation in the TPCs, thermal-coma recovery times, expression of heat-shock proteins and standard metabolic rate (i.e., energetic costs of physiological differentiation). We tested two competing hypotheses regarding thermal adaptation (the “hotter is better” and the generalist-specialist trade-offs). Our results show that the differences in thermal sensitivity among populations of C. aspersum follow a latitudinal pattern, which is likely the result of a combination of thermodynamic constraints (“hotter is better”) and thermal adaptations to their local environments (generalist-specialist trade-offs). This finding is also consistent with some thermal tolerance indices such as the Heat-Shock Protein Response and the recovery time from chill-coma. However, mixed responses in the evaluated traits suggest that thermal adaptation in this species is not complete, as we were not able to detect any differences in neither energetic costs of physiological differentiation among populations, nor in the heat-coma recovery.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000324465000111 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 313  
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Author Lardies, M.A.; Arias, M.B.; Poupin, M.J.; Manriquez, P.H.; Torres, R.; Vargas, C.A.; Navarro, J.M.; Lagos, N.A. pdf  doi
openurl 
  Title Differential response to ocean acidification in physiological traits of Concholepas concholepas populations Type
  Year 2014 Publication Journal Of Sea Research Abbreviated Journal J. Sea Res.  
  Volume 90 Issue Pages 127-134  
  Keywords Environmental gradient; Gastropod; Metabolism; HsP70; Gene expression; Phenotypic flexibility  
  Abstract Phenotypic adaptation to environmental fluctuations frequently occurs by preexisting plasticity and its role as a major component of variation in physiological diversity is being widely recognized. Few studies have considered the change in phenotypic flexibility among geographic populations in marine calcifiers to ocean acidification projections, despite the fact that this type of study provides understanding about how the organism may respond to this chemical change in the ocean. We examined the geographic variation in CO2 seawater concentrations in the phenotype and in the reaction norm of physiological traits using a laboratory mesocosm approach with short-term acclimation in two contrasting populations (Antofagasta and Calfuco) of the intertidal snail Concholepas concholepas. Our results show that elevated pCO(2) conditions increase standard metabolic rates in both populations of the snail juveniles, likely due to the higher energy cost of homeostasis. juveniles of C concholepas in the Calfuco (southern) population showed a lower increment of metabolic rate in high-pCO(2) environments concordant with a lesser gene expression of a heat shock protein with respect to the Antofagasta (northern) population. Combined these results indicate a negative effect of ocean acidification on whole-organism functioning of C. concholepas. Finally, the significant Population x pCO(2) level interaction in both studied traits indicates that there is variation between populations in response to high-pCO(2) conditions. (C) 2014 Elsevier BM. All rights reserved.  
  Address [Lardies, Marco A.; Belen Arias, Maria] Univ Adolfo Ibanez, Fac Artes Liberles, Santiago, Chile, Email: marco.lardies@ual.cl  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 1385-1101 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000337854800013 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 381  
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Author Lardies, M.A.; Arias, M.B.; Poupin, M.J.; Bacigalupe, L.D. pdf  doi
openurl 
  Title Heritability of hsp70 expression in the beetle Tenebrio molitor: Ontogenetic and environmental effects Type
  Year 2014 Publication Journal Of Insect Physiology Abbreviated Journal J. Insect Physiol.  
  Volume 67 Issue Pages 70-75  
  Keywords Animal model; Tenebrio molitor; Thermal adaptation; Thermotolerance; Climate change; Half-sib design  
  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. (C) 2014 Elsevier Ltd. All rights reserved.  
  Address [Lardies, Marco A.] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Santiago, Chile, Email: marco.lardies@uai.cl  
  Corporate Author Thesis  
  Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue (up) Edition  
  ISSN 0022-1910 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000340326900009 Approved  
  Call Number UAI @ eduardo.moreno @ Serial 399  
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