Life in the intertidal: Cellular responses, methylation and epigenetics

Abstract

Abstract1. Phenotypic plasticity is essential for the persistence of organisms under changing environmental conditions but the control of the relevant cellular mechanisms including which genes are involved and the regulation of those genes remains unclear. One way to address this issue is to evaluate links between gene expression, methylation and phenotype using transplantation and common garden experiments within genetically homogeneous populations.2. This approach was taken using the Antarctic limpet Nacella concinna. In this species, two distinct phenotypes are associated with the intertidal and subtidal zones.The in situ gene expression and methylation profiles of intertidal and subtidal cohorts were directly compared before and after reciprocal transplantation as well as after a common garden acclimation to aquarium conditions for 9 months.3. Expression profiles showed significant modulation of cellular metabolism to habitat zone with the intertidal profile characterised by transcription modules for antioxidant production, DNA repair and the cytoskeleton reflecting the need to cope with continually fluctuating and stressful conditions including wave action, UV irradiation and desiccation. 4. Transplantation had an effect on gene expression. The subtidal animals transplanted to the intertidal zone modified their gene expression patterns towards that of an intertidal profile. In contrast, many of the antioxidant genes were still differentially expressed in the intertidal animals several weeks after transplantation into the relatively benign subtidal zone.5. Furthermore, a core of genes involved in antioxidation was still preferentially expressed in intertidal animals at the end of the common garden experiment. Thus, acclimation in an aquarium tank for 9 months did not completely erase the intertidal gene expression profile.6. Significant methylation differences were measured between intertidal and subtidal animals from the wild and after transplantation, which were reduced on common garden acclimation. This suggests that epigenetic factors play an important role in physiological flexibility associated with environmental niche.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Changes in Genome-Wide Methylation and Gene Expression in Response to Future pCO2 Extremes in the Antarctic Pteropod Limacina helicina antarctica

“…This outcome might not be expected if we were to stereotype this species as an Antarctic, cold-adapted invertebrate with diminished cellular responses to environmental change. In fact, studies of environmental epigenetics in two Antarctic marine invertebrates, a benthic polychete and an intertidal gastropod, have both documented differential methylation in response to variation in temperature (Marsh and Pasqualone, 2014;Clark et al, 2018).…”

“…In recent studies of marine metazoans, epigenetic processes have been demonstrated to be associated with the phenotypic plasticity of fitness-related traits in species experiencing climate change-driven stressors (Zhang et al, 2013;Putnam et al, 2016;Clark et al, 2018;Strader et al, 2019;Wong et al, 2019), a relationship that can be explained in part by the link between epigenetic mechanisms, gene expression, translation, and the traits underpinned by these processes (True et al, 2004). For example, experimental manipulation of DNA methylation levels in Arabidopsis thaliana has been shown to substantially alter the phenotypic plasticity of key developmental and physiological traits in low-and high-nutrient environments (Bossdorf et al, 2010).…”

Deciphering mollusc shell production: the roles of genetic mechanisms through to ecology, aquaculture and biomimetics

“…With common garden experiments, animals from different environments are cultivated in common conditions and expected to become more similar and lose the characteristics of their original environments (e.g. Pascoal et al ., 2012; Clark et al ., 2018). Again, a mix of responses occurred with these experiments in different species.…”

“Winners” and “losers” in the Anthropocene: Understanding adaptation through phenotypic plasticity

“…The epigenetic differences seen at the start of the transplant experiments did not persist, although the authors do acknowledge that they may have missed some methylation as it can be extensive across the genome (Huang et al, 2017). Clark et al (2018) have addressed fundamental issues of adaptation but, as is often the case, the animals did not always stick to the plan. The fact that individuals of both transplanted groups began to move back to their source habitats (travelling several metres) highlights some interesting future research themes, for example: (1) why would an organism return to an environment that is demonstrably more stressful; and (2) how does an organism initiate novel behavioural strategies (i.e.…”

“…Clark et al. () have addressed fundamental issues of adaptation but, as is often the case, the animals did not always stick to the plan. The fact that individuals of both transplanted groups began to move back to their source habitats (travelling several metres) highlights some interesting future research themes, for example: (1) why would an organism return to an environment that is demonstrably more stressful; and (2) how does an organism initiate novel behavioural strategies (i.e.…”