Reproductive ecology innovations
Reproductive ecology typically uses old techniques to examine reproductive tissue. Histology is still used to examine gonadal material, and follow similar protocols developed decades ago. I am keen to bring these methods up to date, utilising methods commonly used in medical science, which will enable scientists to examine all reproductive stages, from gonad development, spawning, gamete viability, fertilisation, embryogenesis, larval development, and settlement. All of these reproductive stages have different sensitivities to environmental change, and the failure of one stages will prevent successful reproduction within a population. I see reproduction as one of the most important factors to consider when establishing the effects of environmental change on a population, but only by examining all reproductive stages will the reproductive response be established. The use of emerging technology including sperm auto analysis, 3D scanning microscopy, and fluorescent staining techniques, should be at the forefront of reproductive studies, and utilised to understand relevant effects of change on marine populations.
Transgenerational plasticity in the Southern Ocean
Lissarca notorcadensis on artificial sea urchin spines from the Weddell Sea, Antarctica
My previous research investigates the role of transgenerational plasticity (TGP) in ameliorating the effects of climate change over generations. TGP is a mechanism of adapting to changing conditions, where the offspring of adults exposed to an environmental stress are better adapted to that situation. It is a rapid response to change, but different to acclimation and plasticity which occurs within individuals of a generation, or developmental plasticity which occurs during offspring development. How TGP occurs and the role it may have on marine invertebrates is of interest to scientists, as it provides a better indicator of survival to changing conditions. To date, long-term laboratory studies on Southern Ocean invertebrates have not investigated TGP, partly due to the difficulties in obtaining short lived species and unknown husbandry. My unique skills and background in the ornamental aquarium trade have however provided me with the opportunity to design a concept aquarium system which can deliver long-term TGP experiments.
I am particularly interested in the proteomic aspects of plasticity, both within generation and across generations, to increasing sea temperatures. Proteomics provides a real insight into how and where changes occur, and modern cutting edge techniques allow us to measure these changes in detail. The proteome potentially underpins acclimation and plasticity as it can change independently of genetic or transcriptomic controls. Selection in a natural environment will typically act upon the phenotype of an organism, and the phenotype is the product of the proteome. While genomic and transcriptomic approaches appear more common in the literature, the rate of change in the proteome is higher than that of the genome. Additionally, post-translational modifications, alternative splicing, and protein turnover/degradation rates, can change the function and abundance of expressed proteins, undetectable from genomic and transcriptomic analysis. Changes in the proteome between naturally derived organisms, and offspring produced under an environmental stress, give molecular insight into the role of plasticity and specifically TGP as an adaptive response.
I am particularly interested in the proteomic aspects of plasticity, both within generation and across generations, to increasing sea temperatures. Proteomics provides a real insight into how and where changes occur, and modern cutting edge techniques allow us to measure these changes in detail. The proteome potentially underpins acclimation and plasticity as it can change independently of genetic or transcriptomic controls. Selection in a natural environment will typically act upon the phenotype of an organism, and the phenotype is the product of the proteome. While genomic and transcriptomic approaches appear more common in the literature, the rate of change in the proteome is higher than that of the genome. Additionally, post-translational modifications, alternative splicing, and protein turnover/degradation rates, can change the function and abundance of expressed proteins, undetectable from genomic and transcriptomic analysis. Changes in the proteome between naturally derived organisms, and offspring produced under an environmental stress, give molecular insight into the role of plasticity and specifically TGP as an adaptive response.
Physiological plasticity in the deep Southern Ocean
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In 2012, I participated on research cruise JR275 to the Weddell Sea on board the RRS James Clark Ross with the British Antarctic Survey. Whilst on board, I was able to conduct an acute thermal shock experiment on two populations of the bivalve Lissarca notorcadensis from 300 and 600 metres depth in the Scotia and Weddell Seas, respectively (Reed and Thatje 2015). This study was a rare opportunity to investigate differences in upper thermal thresholds in deep-water environments between two subtly contrasting sites, which had not been conducted using invertebrates collected at depth before. The results demonstrated that the slightly more variable temperatures associated with the Scotia sea shelf depths had likely resulted in a population far more able to acclimate to acute warming, and this population were able to survive at water temperatures twice as high as those in the Weddell Sea. This was a significant result as it shows the potential for adaptation to variable conditions over time, which is largely thought to be constrained in the Southern Ocean where life has evolved in stable and extremely cold conditions.
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Oxygen consumption of the Antarctic bivalve Lissarca notorcadensis
under thermally controlled conditions. Closed circle Scotia
Sea (n = 9); open circle Weddell Sea (n = 15); a oxygen consumption
and standard deviation after increasing temperatures with 6 h of
acclimation every 1 °C, and a maximum of 24-h isolation period. Red
symbol 50 % mortality. Taken from Reed et al. 2015.
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Plasticity in Southern Ocean bivalves
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Plasticity is the ability of a single genotype to express many phenotypes as is an extremely common mechanism to allow acclimation to the conditions at the time. While it can been commonly described globally in all all ecosystems, aquatic and terrestrial, the Southern Ocean and deep sea has received the least amount of attention. This is largely because it is difficult to sample the fauna in the same area on a regular basis and it is difficult to bring them back for analysis. During my PhD I studied this plasticity in shelled molluscs from Signy Island Antarctica, and from the deep Weddell, Scotia, and Amundsen seas. My studies revealed phenotypic and reproductive plasticity across geographic ranges, depth, and over time. Plasticity over space and depth had rarely been reported in the Southern Ocean and added to the growing literature on plasticity in cold environments.
Of most interest however were my observations of different shell shape, growth rates, reproductive traits, and shell condition over a forty year period at Signy Island (Published in PLoS ONE Reed et al. 2012). Using museum samples on loan from the National Museum Wales, and samples held at the British Antarctic Survey, I found a plastic response which correlated with a four decade atmospheric warming event. This astonishing result demonstrated the impact of warming on intertidal Antarctic ecosystems, but also demonstrated a potential for adaptation through transgenerational plasticity. This challenges the long standing paradigm of low acclimation and high sensitivity to warming in Southern Ocean invertebrates, which are largely derived from within generation acute shock experiments. |
Lissarca miliaris from Signy Island, Antarctica, collected in 1976
Different shell shapes of Lissarca miliaris from different locations in the Southern Ocean. Taken from Reed et al. 2014
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