Papers by Ioanna Katsiadaki
Evolutionary Ecology Research, 2016
Background: The Arctic is subject to atmospheric deposition of persistent organic pollutants thro... more Background: The Arctic is subject to atmospheric deposition of persistent organic pollutants through the process of global distillation. It also contains thousands of sites with local sources of contamination, including military installations, mining operations, and petroleum extraction facilities. Pollutants accumulate in surface waters. Aim: To investigate the utility of ninespine stickleback (Pungitius pungitius) as a sentinel fish species to monitor the presence and biological effects of chemical contamination in the Arctic. Organism: Pungitius pungitius is a circumpolar species that occurs in freshwater, brackish water, and marine habitats. It is often the most abundant fish present. It appears to be relatively hardy with respect to potentially lethal effects of contaminants, which allows investigation of perturbed biological processes such as endocrine, gene expression, and developmental disruption. Biomarker development: We developed a homologous vitellogenin assay for the ni...
Diseases of Aquatic Organisms
Enteric redmouth disease (ERM) caused by the enterobacterium Yersinia ruckeri poses a significant... more Enteric redmouth disease (ERM) caused by the enterobacterium Yersinia ruckeri poses a significant threat to salmonid aquaculture globally. Despite decades of experimental infection studies, key knowledge gaps remain regarding the onset of disease susceptibility and mechanisms of immunity during early developmental stages, undermining disease management efforts in all susceptible life-stages. In this study, a series of immersion challenges were conducted, challenging and re-challenging rainbow trout Oncorhynchus mykiss (Walbaum) at 7, 14 and 51 d post-hatch (dph; mean weights = 0.085, 0.1 and 2.0 g respectively) to high concentrations (1.72 × 107-1.1 × 108 CFU) of Y. ruckeri at 15°C. This study indicates the hitherto unknown initial point of susceptibility to infection as the time of first ingestion of exogenous food (14 dph), and shows that individuals surviving primary challenge at 14 dph are significantly more likely to survive re-challenge at 51 dph compared with naive individual...
The potential of developing a biomarker for androgens in the three-spined stickleback (via the ki... more The potential of developing a biomarker for androgens in the three-spined stickleback (via the kidney glue protein that breeding males use to construct a nest) was recognised 10 years ago. As a consequence, under the UK EDMAR programme an ELISA for the only known so far androgen-regulated protein in fish, the stickleback glue spiggin, was developed and validated. More recently the stickleback assay was modified in two different ways to detect anti-androgens, a group of EDCs that poses an increasing risk to the aquatic environment as the in vitro data obtained from two nationwide surveys of final sewage effluents suggest. Importantly, the stickleback is present in Europe (and across all of the North hemisphere) and can bring together lab and field studies providing a sound basis for environmental risk assessment. To this end, the UK (Defra CN) has financed three research programmes that underpinned the background and validation data requirements that could lead to the inclusion of th...
Scientific Reports, 2020
Model fish species such as sticklebacks and zebrafish are frequently used in studies that require... more Model fish species such as sticklebacks and zebrafish are frequently used in studies that require DNA to be collected from live animals. This is typically achieved by fin clipping, a procedure that is simple and reliable to perform but that can harm fish. An alternative procedure to sample DNA involves swabbing the skin to collect mucus and epithelial cells. Although swabbing appears to be less invasive than fin clipping, it still requires fish to be netted, held in air and handled—procedures that can cause stress. In this study we combine behavioural and physiological analyses to investigate changes in gene expression, behaviour and welfare after fin clipping and swabbing. Swabbing led to a smaller change in cortisol release and behaviour on the first day of analysis compared to fin clipping. It also led to less variability in data suggesting that fewer animals need to be measured after using this technique. However, swabbing triggered some longer term changes in zebrafish behaviou...
Evolutionary Ecology Research, 2016
Background: Female threespine sticklebacks, Gasterosteus aculeatus, are batch spawners. As in mos... more Background: Female threespine sticklebacks, Gasterosteus aculeatus, are batch spawners. As in most teleosts, the ovulated eggs are kept in the ovarian cavity until spawning. If spawning or spontane ...
The 21-day androgenised female stickleback endocrine screening assay
Scientific Reports, Jun 18, 2021
The monitoring of anthropogenic chemicals in the aquatic environment including their potential ef... more The monitoring of anthropogenic chemicals in the aquatic environment including their potential effects on aquatic organisms, is important for protecting life under water, a key sustainable development goal. In parallel with monitoring the concentrations of chemicals of concern, sentinel species are often used to investigate the biological effects of contaminants. Among these, bivalve molluscs such as mussels are filter-feeding and sessile, hence an excellent model system for measuring localized pollution. This study investigates the relationship between the metabolic state of the blue mussel (Mytilus edulis) and its physiology in different environments. We developed a computational model based on a reference site (relatively unpolluted) and integrated seasonal dynamics of metabolite relative concentrations with key physiological indicators and environmental parameters. The analysis of the model revealed that changes in metabolite levels during an annual cycle are influenced by water temperature and are linked to gonadal development. This work supports the importance of data-driven biology and its potential in environmental monitoring. Anthropogenic pollution affects water quality and consequently represents a threat for ecosystem and human health (UN report, 2019). The increase in new chemicals released into aquatic ecosystems requires continuous development of monitoring techniques, especially concerning the detection of early biotic effects of chemical contamination. In the European Union, for the marine environment, this monitoring is performed under the Marine Water Framework Directive (MSFD) 1. The MSFD aims to provide and support healthy marine ecosystems by establishing Good Environmental Status as set out by several environmental descriptors including, but not limited to, biological diversity, eutrophication, marine litter and anthropogenic contaminants. Currently, chemical contaminant monitoring is undertaken by measuring levels of targeted contaminants in water, sediment and biota. In addition, sensitive indicator species are used as sentinels to assess ecosystem health through the use of biomarkers, thus providing additional information on the biological effects of environmental pollutants 2. A few of these markers have been proven useful; for example vitellogenin presence in the plasma of male and juvenile fish is a robust biomarker of exposure to oestrogenic chemicals 3-5. Molecular tools have been proposed as a sensitive approach capable of detecting organism-level effects very early on, with potential predictive power in determining a future deterioration of a populations fitness 6-9. The advent of functional genomics technologies provides powerful tools that can be used to identify more complex molecular signatures that are predictive of toxicity 10-17. Mussels represent an excellent indicator species due to their wide ranging habitat, including both salt and freshwater, geographical distribution and their ability to filter vast amounts of water (e.g. Mytilus edulis can filter up to 15 ml water in a minute) 18-22. Mussels have been used to monitor contaminants long before the advent of functional genomics technologies 21. Whole organism biomarkers of toxic effects in mussels, such as scope for
Current Opinion in Environmental Science & Health, Oct 1, 2019
Are marine invertebrates really at risk from endocrine disrupting chemicals? Ioanna Katsiadaki Ce... more Are marine invertebrates really at risk from endocrine disrupting chemicals? Ioanna Katsiadaki Centre for environment, fisheries and aquaculture science (Cefas),
Marine biology, Dec 15, 2006
Aquatic Toxicology, May 1, 2010
An established three-spined stickleback (Gasterosteus aculeatus) cDNA array was expanded to 14,49... more An established three-spined stickleback (Gasterosteus aculeatus) cDNA array was expanded to 14,496 probes with the addition of hepatic clones derived from subtractive and normalized libraries from control males and males exposed to model toxicants. Microarrays and one-dimensional 1 H nuclear magnetic resonance (NMR) spectroscopy, together with individual protein and gene biomarkers were employed to investigate the hepatic responses of the stickleback to ethinyl-estradiol (EE 2) exposure. Male fish were exposed via the water to EE 2 , including environmentally relevant concentrations (0.1-100 ng/l) for 4 days, and hepatic transcript and metabolite profiles, kidney spiggin protein and serum vitellogenin concentrations were determined in comparison to controls. EE 2 exposure did not significantly affect spiggin concentration but significantly induced serum vitellogenin protein at the threshold concentration of 32 ng/l. 1 H NMR coupled with robust univariate testing revealed only limited changes, but these did support the predicted modulation of the amino acid profile by transcriptomics. Transcriptional induction was found for hepatic vitellogenins and choriogenins as expected, together with a range of other EE 2-responsive genes. Choriogenins showed the more sensitive responses with statistically significant induction at 10 ng/l. Real-time polymerase chain reaction (PCR) confirmed transcriptional induction of these genes. Phosvitinless vitellogenin C transcripts were highly expressed and represent a major form of the egg yolk precursors, and this is in contrast to other fish species where it is a minor component of vitellogenic transcripts. Differences in inducibility between the vitellogenins and choriogenins appear to be in accordance with the sequential formation of chorion and yolk during oogenesis in fish.
The Journal of Steroid Biochemistry and Molecular Biology, 2017
Scientific Reports, 2019
Development requires the implementation of a plethora of molecular mechanisms, involving a large ... more Development requires the implementation of a plethora of molecular mechanisms, involving a large set of genes to ensure proper cell differentiation, morphogenesis of tissues and organs as well as the growth of the organism. Genome duplication and resulting paralogs are considered to provide the raw genetic materials important for new adaptation opportunities and boosting evolutionary innovation. The present study investigated paralogous genes, involved in three-spined stickleback (Gasterosteus aculeatus) development. Therefore, the transcriptomes of five early stages comprising developmental leaps were explored. Obtained expression profiles reflected the embryo’s needs at different stages. Early stages, such as the morula stage comprised transcripts mainly involved in energy requirements while later stages were mostly associated with GO terms relevant to organ development and morphogenesis. The generated transcriptome profiles were further explored for differential expression of kno...
Journal of fish biology, 2018
Wild fish populations are currently experiencing unprecedented pressures, which are projected to ... more Wild fish populations are currently experiencing unprecedented pressures, which are projected to intensify in the coming decades. Developing a thorough understanding of the influences of both biotic and abiotic factors on fish populations is a salient issue in contemporary fish conservation and management. During the 50th Anniversary Symposium of The Fisheries Society of the British Isles at the University of Exeter, UK, in July 2017, scientists from diverse research backgrounds gathered to discuss key topics under the broad umbrella of 'Understanding Fish Populations'. Below, the output of one such discussion group is detailed, focusing on tools used to investigate natural fish populations. Five main groups of approaches were identified: tagging and telemetry; molecular tools; survey tools; statistical and modelling tools; tissue analyses. The appraisal covered current challenges and potential solutions for each of these topics. In addition, three key themes were identified...
Data in Brief, Dec 1, 2016
The data presented in this article primarily provide support for the research article entitled "M... more The data presented in this article primarily provide support for the research article entitled "Mussels (Mytilus spp.) display an ability for rapid and high capacity uptake of the vertebrate steroid, estradiol-17β from water" (T.I. Schwarz, I. Katsiadaki, B.H. Maskrey, A.P. Scott, 2016) [1]. Data are presented on the ability of mussels to absorb tritiated estradiol (E 2) from water. The data indicate that most of the radioactivity remaining in the water is 1,3,5(10)estratriene-3,17β-diol 3-sulfate (E 2 3-S) and the radioactivity in the mussel tissue is mainly in the form of fatty acid esters. The latter, following saponification, were identified by ultra-high performance liquid chromatography in conjunction with tandem mass spectrometry (UHPLC-MS/MS) as intact E 2. Data are included that indicate that the remaining radioactivity in the tissue is composed of E 2 3-S and unidentified free metabolites. Experimental data included also relate to a) the efficiency of extraction of radioactivity from tissue, b) the efficiency of separation of free and esterified E 2 using solvents and c) possible factors affecting the recovery of radioactivity. Finally, preliminary data are provided on concentrations of immunoreactive E 2 in the free and ester fractions of tissue extracts from mussels caged in the field.
Diseases of Aquatic Organisms, 2023
Enteric redmouth disease (ERM) caused by the enterobacterium Yersinia ruckeri poses a significant... more Enteric redmouth disease (ERM) caused by the enterobacterium Yersinia ruckeri poses a significant threat to salmonid aquaculture globally. Despite decades of experimental infection studies, key knowledge gaps remain regarding the onset of disease susceptibility and mechanisms of immunity during early developmental stages, undermining disease management efforts in all susceptible life-stages. In this study, a series of immersion challenges were conducted, challenging and re-challenging rainbow trout Oncorhynchus mykiss (Walbaum) at 7, 14 and 51 d post-hatch (dph; mean weights = 0.085, 0.1 and 2.0 g respectively) to high concentrations (1.72 × 107-1.1 × 108 CFU) of Y. ruckeri at 15°C. This study indicates the hitherto unknown initial point of susceptibility to infection as the time of first ingestion of exogenous food (14 dph), and shows that individuals surviving primary challenge at 14 dph are significantly more likely to survive re-challenge at 51 dph compared with naive individuals (hazard ratio = 1.446, p = 0.032). Other key findings include large variation in mortality between different development-stages, from 21.1% at 14 dph to 81.2% at 51 dph, and novel age-dependent symptoms not reported previously. Results from this study enhance our understanding of ERM in juvenile rainbow trout and inform the development of improved aquatic animal health management strategies, thereby contributing to the productivity and sustainability of salmonid aquaculture into the future.
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Papers by Ioanna Katsiadaki