ProTEoME - PROteomic Tools to assess Endocrine disruptiOn MEchanisms

Funder

Organizational Unit

Publications

Epigenetics in aquaculture: the last frontier

Publication . Granada, Luana; Lemos, Marco F.L.; Cabral, Henrique N.; Bossier, Peter; Novais, Sara C.

Aquaculture production is expanding rapidly around the world. To tackle rising production and species diversity issues, innovations in the field of aquaculture feeds, breeding, disease management and other improvements must be addressed. In this framework, the study of epigenetic mechanisms behind different aquaculture rearing processes presents great opportunities. The transcriptional impact of epigenetic modifications, triggered by environmental stimuli, has been shown to influence the organism’s phenotype. Therefore, understanding the environmental-induced epigenetic markers related to disease resistance or other economically important traits will allow the establishment of favourable breeding conditions with increased economical revenue. Several studies have shown epigenetic effects in various species, induced by different rearing conditions, with benefits for the organisms and evidences for heritability of the acquired adaptive phenotypic traits across generations, making these studies even more relevant in a production context. These studies have demonstrated the great potential of epigenetics to positively induce disease resistance, stress tolerance and attain better sex ratios in the aquatic organism. Also, in the field of nutritional epigenetics, the possibility of early nutritional programming to improve the performance of broodstock or even the long-term performance of their progeny has been suggested. In sum, an increased understanding of epigenetic mechanisms in economically important species, and the epigenetic markers leading to the most favourable phenotypic traits, will contribute to the expansion of economically viable commercial aquaculture industries. The major epigenetic mechanisms and respective analysis methods, as well as the state of the art and potential applications in aquaculture, are addressed in this review.

2018Journal article

Restricted access

Chemical predator signals induce metabolic suppression in rock goby (Gobius paganellus)

Publication . Paul, Nina; Novais, Sara C.; Lemos, Marco F. L.; Kunzmann, Andreas

In nature, a multitude of both abiotic and biotic stressors influence organisms with regard to their overall fitness. Stress responses that finally impair normal biological functions may ultimately result in consequences for whole populations. This study focused on the metabolic response of the intertidal rock pool fish Gobius paganellus towards simulated predation risk. Individuals were exposed to a mixture of skin extracts from conspecifics and chemical alarm cues from a top predator, Octopus vulgaris. Oxygen consumption rates of single fish were measured to establish standard (SMR) and routine metabolic rates (RMR) of G. paganellus, and to address the direct response towards simulated predation risk, compared to handling and light stress. The SMR of G. paganellus (0.0301 ± 0.0081 mg O2 h-1 g-1 WW) was significantly lower than the RMR (0.0409 ± 0.0078 mg O2 h-1 g-1 WW). In contrast to increased respiration due to handling and light stress, the exposure to chemical predation cues induced a significant reduction in oxygen consumption rates (0.0297 ± 0.0077 mg O2 h-1 g-1 WW). This metabolic suppression was interpreted as a result of the stereotypic freezing behaviour as antipredator response of gobiid fish. Results underline the importance of biotic interactions in environmental stress assessments and predation as a biotic factor that will provide more realistic scenarios when addressing stress impacts in tidal rock pool organisms.

2018Journal article

Open access

Oxidative stress responses and cellular energy allocation changes in microalgae following exposure to widely used human antibiotics

Publication . Aderemi, Adeolu O.; Novais, Sara C.; Lemos, Marco F.L.; Alves, Luís M.; Hunter, Colin; Pahl, Ole

The individual effect of four human antibiotics on the microalgae Raphidocelis subcapitata was investigated following a 120-h exposure. The effects were assessed by analyzing growth, and biochemical parameters related with: 1) antioxidant capacity and oxidative damage by measuring superoxide dismutase (SOD) activity and lipid peroxidation (LPO) levels; and 2) cellular energy allocation (CEA) by quantifying the content in energy reserves, which represents the energy available (Ea), and the electron transport system activity that represents a measure of oxygen and cellular energy consumption (Ec). Growth yield inhibitory concentrations of sulfamethoxazole (18–30%), clarithromycin (28.7%), ciprofloxacin (28%) and erythromycin (17–39%) were found to elicit a considerable increase in Ec, thereby causing a significant decrease in the CEA. The elevated Ec can be a result of the need to respond to oxidative stress occurring under those conditions given the significant increase in SOD activity at these levels. For sulfamethoxazole, erythromycin and ciprofloxacin, the antioxidant responses do not seem to be enough to cope with the reactive oxygen species and prevent oxidative damage, given the elevated LPO levels observed. A stimulatory effect on growth yield was observed (up to 16%) at ciprofloxacin lowest concentration, which highly correlated with the increase in CEA. Based on the no observed effect concentration (NOECs) and/or effective concentration (EC10) results, Ec, SOD and CEA were more sensitive than the classical endpoint of growth rate for all the tested antibiotics. By revealing the antibiotic stress effects in R. subcapitata at the cellular level, this study suggests CEA as a more reliable indicator of the organisms’ physiological status.

2018Journal article

Restricted access

Amitraz toxicity to the midge Chironomus riparius: Life-history and biochemical responses

Publication . Monteiro, Hugo R.; Lemos, Marco F. L.; Novais, Sara C.; Soares, Amadeu M. V. M.; Pestana, João L. T.

Acute and chronic toxicity of the formamidine pesticide amitraz to the midge Chironomus riparius was assessed using conventional ecotoxicological tests and biochemical approaches (biomarkers). Amitraz is mainly used as an ectoparasiticide in veterinary medicine, but also in agriculture and apiculture. However, information of amitraz toxicity to non-target invertebrates is limited. Besides the impairment of developmental and emergence rates (reduced larval growth, emergence, and delayed development time) caused by chronic exposure to amitraz, acute exposures induced alterations in the antioxidant enzymes glutathione peroxidase (GPx) and catalase (CAT), and in energetic metabolism biomarkers, lactate dehydrogenase (LDH) and electron transport system (ETS) activities. Moreover, lipid peroxidation (LPO) increased by amitraz exposure. Our results reveal potential secondary effects of amitraz to invertebrates and biomarkers that may aid in the interpretation of sub-lethal toxic responses to amitraz. These results add information concerning the potential outcomes of amitraz exposure to freshwater invertebrates underlining the importance of risk assessment studies of formamidine pesticides.

2019-01Journal article

Restricted access

Sand smelt ability to cope and recover from ocean's elevated CO 2 levels

Publication . Silva, Cátia S. E.; Lemos, Marco F. L.; Faria, Ana M.; Lopes, Ana F.; Mendes, Susana; Gonçalves, Emanuel J.; Novais, Sara C.

Considered a major environmental concern, ocean acidification has induced a recent research boost into effects on marine biodiversity and possible ecological, physiological, and behavioural impacts. Although the majority of literature indicate negative effects of future acidification scenarios, most studies are conducted for just a few days or weeks, which may be insufficient to detect the capacity of an organism to adjust to environmental changes through phenotypic plasticity. Here, the effects and the capacity of sand smelt larvae Atherina presbyter to cope and recover (through a treatment combination strategy) from short (15 days) and long-term exposure (45 days) to increasing pCO2 levels (control: ~515 μatm, pH = 8.07; medium: ~940 μatm, pH = 7.84; high: ~1500 μatm, pH = 7.66) were measured, addressing larval development traits, behavioural lateralization, and biochemical biomarkers related with oxidative stress and damage, and energy metabolism and reserves. Although behavioural lateralization was not affected by high pCO2 exposure, morphometric changes, energetic costs, and oxidative stress damage were impacted differently through different exposures periods. Generally, short-time exposures led to different responses to either medium or high pCO2 levels (e.g. development, cellular metabolism, or damage), while on the long-term the response patterns tend to become similar between them, with both acidification scenarios inducing DNA damage and tending to lower growth rates. Additionally, when organisms were transferred to lower acidified condition, they were not able to recover from the mentioned DNA damage impacts. Overall, results suggest that exposure to future ocean acidification scenarios can induce sublethal effects on early life-stages of fish, but effects are dependent on duration of exposure, and are likely not reversible. Furthermore, to improve our understanding on species sensitivity and adaptation strategies, results reinforce the need to use multiple biological endpoints when assessing the effects of ocean acidification on marine organisms.

2018Journal article

Open access