Epigenetics in aquaculture – the last frontier

Abstract

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.

Prospects for incorporation of epigenetic biomarkers in human health and environmental risk assessment of chemicals

“…Daphnia and Artemia are two suitable invertebrate candidates: in species of both genera, epigenetic marks that potentially serve as biological markers of exposure have already been identified for several natural stressors (Norouzitallab et al ., ; Trijau et al ., ; Jeremias et al ., ). Both have great potential as epigenetic model organisms since there is a very large ecological, ecotoxicological and evolutionary literature available for these species, and clonal populations can be easily established and maintained in the laboratory (Harris et al ., ; Granada et al ., ; Norouzitallab et al ., ). In addition, draft genome sequences of Daphnia magna and Daphnia pulex are available and their reproductive strategy facilitates transgenerational studies and allows the elimination of genetic variability (Harris et al ., ; Bell & Stein, ; Brander et al ., ).…”

Somatotropic Axis Regulation Unravels the Differential Effects of Nutritional and Environmental Factors in Growth Performance of Marine Farmed Fishes

“…Igfbps are emerging as highly regulated components of the Gh/Igf system, though the puzzle is far from complete because their tissue-specific regulation has not been established for all paralogs across fish species and different physiological conditions. Thus, further research is needed to combine the search for a robust, highly specific set of biomarkers for a given growth derangement, which may have an impact later in life by means of different epigenetic mechanisms, involving changes in DNA methylation and histone acetylation, among others ( 228 ).…”

Antiviral Defense and Innate Immune Memory in the Oyster

“…It is not currently known how the oyster’s immune system is able to store information regarding previously encountered virus antigens (i.e., dsRNA or polyI:C) to induce resistance upon secondary exposure to a virus. One intriguing possibility is an epigenetic mechanism, such as DNA methylation or non-coding RNA that elevates the constitutive gene expression of antiviral effectors [ 89 , 90 ]. This would allow the oyster’s innate immune system to have plasticity (i.e., memory), as evidenced by the significant upregulation of oyster ISGs for at least seven days following polyI:C stimulation [ 91 ].…”