Percorrer por autor "Bossier, Peter"
A mostrar 1 - 6 de 6
Resultados por página
Opções de ordenação
- Epigenetics in aquaculture - the last frontierPublication . Granada, Luana; Lemos, Marco F. L.; Cabral, Henrique; 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.
- Epigenetics in aquaculture: the last frontierPublication . 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.
- Genetic identification and comparative study on life history parameters of two strains belonging to Brachionus plicatilis species complex (Rotifera: Monogononta)Publication . Granada, Luana; Lemos, Marco F.L.; Bossier, Peter; Novais, Sara C.The rotifer Brachionus plicatilis is an important species for aquaculture, due to its use as food for bivalves, and fish and crustaceans larvae in hatcheries. However, being a species complex, it has become increasingly important to catalogue and describe the species and biotypes that constitute this complex. Therefore, the purpose of this study was to genetically identify two morphologically identical strains and evaluate their suitability to be used in aquaculture under the studied conditions. A correct identification and knowledge of life history characteristics of the biotypes and isolated strains is vital to avoid mass mortalities in aquaculture and to better interpret the responses of the organisms when these are used as a bioindicator and model for ecotoxicology. Strains MRS10 and IBA3 were identified as B. koreanus and, even though they have been maintained under the same laboratory conditions for several years, significant differences in several life history parameters were observed. A life table assay showed IBA3 rotifers to be larger at first reproduction, and to have longer post-reproductive period and mean lifespan. On the other hand, MRS10 rotifers produced less non-viable eggs and had higher population growth rate. Both strains showed to be a potential model for ecotoxicological and molecular studies, mainly due to the ease of maintenance, short generation time, and reproduction via parthenogenesis. However, MRS10 might present better characteristics than IBA3 to be reared in aquaculture as live food.
- Non-lethal heat shock increases tolerance to metal exposure in brine shrimpPublication . Pestana, João L.T.; Novais, Sara; Norouzitallab, Parisa; Vandegehuchte, Michiel B.; Bossier, Peter; De Schamphelaere, Karel A.C.Pollution and temperature increase are two of the most important stressors that aquatic organisms are facing. Exposure to elevated temperatures and metal contamination both induce heat shock proteins (HSPs), which may thus be involved in the induced cross-tolerance in various organisms. This study aimed to test the hypothesis that exposure to a non-lethal heat shock (NLHS) causes an increased tolerance to subsequent metal exposure. Using gnotobiotic cultures of the brine shrimp Artemia franciscana, the tolerance to Cd and Zn acute exposures was tested after a prior NLHS treatment (30 min exposure to 37 °C). The effects of NLHS and metal exposure were also assessed by measuring 70 kDa-HSPs production, along with the analysis of epigenetic markers such as DNA methylation and histone H3 and histone H4 acetylation. Our results showed that heat-shocked Artemia had increased acute tolerance to Cd and Zn. However, different patterns of HSPs were observed between the two metal compounds and no epigenetic alterations were observed in response to heat shock or metal exposure. These results suggest that HSP production is a phenotypically plastic trait with a potential role in temperature-induced tolerance to metal exposure.
- Non-lethal heat shock induces cross-tolerance to different stressors in two strains of Brachionus koreanus (Rotifera: Monogononta): Mechanisms of increased tolerance to hydrogen peroxidePublication . Granada, Luana; Morão, Inês F.C.; Lemos, Marco F. L.; Bossier, Peter; Novais, Sara C.The rotifer Brachionus sp. is of great importance for aquaculture, as the reproduction cycle under rearing conditions of many economically important species larvae depends on the use of rotifers as first live feed. Establishing a protocol that results in an improved tolerance of rotifers to environmental stressors will allow for a more stable rotifer production. The exposure to non-lethal heat shocks (NLHS) already proved to enhance the tolerance, not only to heat stress, but also to other stressors in several aquatic species, by activating the heat shock response and epigenetic mechanisms. This study aimed to determine the potential of a single NLHS to induce tolerance to different abiotic stressors in two strains of B. koreanus (MRS10 and IBA3) and to evaluate possible molecular mechanisms involved in the achievement of increased tolerance to hydrogen peroxide induced by NLHS. Cross-tolerance was achieved for both strains, namely to high salinity, cadmium chloride, and hydrogen peroxide. Scale-up tests resulted in increased tolerance to hydrogen peroxide only for MRS10. During the exposure to this substance, heat-shocked MRS10 rotifers showed an up-regulation of genes related to oxidative stress response and histone modifications, increased production of HSP70, and higher levels of total acetylation of histone H3. A single NLHS proved to induce epigenetic effects when rotifers were exposed to other stressor later in life. However, further studies should elucidate if the NLHS conditions used in this study can yield a persistent outcome, allowing the establishment of tolerant rotifer strain lines and, consequently, a more stable production.
- Swimming behaviour as an alternative endpoint to assess differences in abiotic stress sensitivities between strains of Brachionus koreanus (Rotifera: Monogononta)Publication . Granada, Luana; Lemos, Marco F.L.; Bossier, Peter; Novais, Sara C.Brachionus plicatilis is a cosmopolitan rotifer used as a model organism in several research areas and as live food in aquaculture. Being a species complex, responses to stressors vary even among strains of the same species and, thus, the responses of one species are not representative of the whole complex. This study aimed to address the effects of extreme salinity ranges, and different concentrations of hydrogen peroxide, copper, cadmium, and chloramphenicol, in two strains of B. koreanus (MRS10 and IBA3) from B. plicatilis species complex, by assessing effects on their survival and swimming capacity. Neonates (0–4 h old) were exposed to the stressors in 48 well-microplates, for 24 and 6 h, to evaluate lethal and behavioural effects, respectively. Tested conditions of chloramphenicol did not show any effects on rotifers. The behavioural endpoint showed to be particularly sensitive to assess the effects of high salinity, hydrogen peroxide, and copper sulfate, as swimming capacity impairment was observed for both strains in the lowest concentrations used in lethal tests. Overall, results showed that IBA3 was more tolerant to the majority of stressors, comparing to MRS10, which may be due to differences in physiological characteristics, highlighting the importance of performing multiclonal experiments. Also, swimming capacity inhibition proved to be a good alternative to the classical lethality tests, being sensitive to lower concentrations and with shorter exposure periods.