title: Age-related thermal response: the cellular resilience of juveniles.
abstract: Understanding species' responses to environmental challenges is key to predicting future biodiversity. However, there is currently little data on how developmental stages affect responses and also whether universal gene biomarkers to environmental stress can be identified both within and between species. Using the Antarctic clam, Laternula elliptica, as a model species, we examined both the tissue-specific and age-related (juvenile versus mature adult) gene expression response to acute non-lethal warming (12 h at 3 °C). In general, there was a relatively muted response to this sub-lethal thermal challenge when the expression profiles of treated animals, of either age, were compared with those of 0 °C controls, with none of the "classical" stress response genes up-regulated. The expression profiles were very variable between the tissues of all animals, irrespective of age with no single transcript emerging as a universal biomarker of thermal stress. However, when the expression profiles of treated animals of the different age groups were directly compared, a very different pattern emerged. The profiles of the younger animals showed significant up-regulation of chaperone and antioxidant transcripts when compared with those of the older animals. Thus, the younger animals showed evidence of a more robust cellular response to warming. These data substantiate previous physiological analyses showing a more resilient juvenile population.
authors.affiliation: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK. mscl@bas.ac.uk.
authors.forename: M S
authors.initials: MS
authors.lastname: Clark
authors.affiliation: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: M A S
authors.initials: MAS
authors.lastname: Thorne
authors.affiliation: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: G
authors.initials: G
authors.lastname: Burns
authors.affiliation: British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: L S
authors.initials: LS
authors.lastname: Peck
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000367:Age Factors; D000818:Animals; D000864:Antarctic Regions; D000975:Antioxidants / Q000378:metabolism; D001483:Base Sequence; D049872:Bivalvia; D000091342:Endoplasmic Reticulum Chaperone BiP; D004781:Environmental Exposure; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D013482:Superoxide Dismutase
keywords: GRP78; Heat shock protein; Immune; MAP kinase; Superoxide dismutase; Tissue-specific