238
M.L. Cancela et al.
toxicological evaluation. Firstly, their high throughput nature means that it is possible to analyze multiple tissues in a timely and cost-effective manner. In addition,
DNA amplification is much less time consuming and can easily provide identification of biological contaminants such as microorganisms or viruses. Secondly, by
applying transcriptomics, proteomics and metabolomics the full range of biological
responses from gene expression to cellular functions can be studied.
7.5.4.1 Health Hazards in Seafood
The development and application of DNA-based analytical techniques to ensure
seafood safety is currently the object of intense research efforts. Major hazards in
terms of the safety of seafood products are: toxic compounds (e.g. environmental chemical pollutants, biotoxins), viruses, bacteria and parasites. Nowadays, gene
expression measured by DNA microarrays is believed to provide a more comprehensive, sensitive and characteristic insight into toxicity than typical toxicological
parameters such as morphological changes, altered reproductive capacity or mortality (Steinberg et al. 2008). In recent years, the generation of EST databases for
species important in aquaculture and aquatic toxicology, have resulted in the development of DNA microarray platforms where expression of multiple genes can be
assessed simultaneously, following exposure to environmental pollutants and natural
environmental chemical stressors. Furthermore, expression profiling is an appealing
alternative in ecotoxicological screening, both due to the possibility of monitoring
multiple classical toxicological biomarker genes simultaneously and the possible
discovery of novel biomarkers (for review see Battershill 2005, Heijne et al. 2005,
Brul et al. 2006).
7.5.4.2 Allergenicity in Seafood Products
Seafood allergies are a significant public health concern throughout the world and
although certainly overestimated in the public perception, they are most prevalent
in coastal populations where the consumption and processing of fish and shellfish
are high, such as in Scandinavia and Iberian Peninsula countries. Major seafood
allergens identified are the Ca 2+ -binding proteins, parvalbumin in fish and muscle
tropomyosin (Pen a1) and arginine kinase (Pen a2) in shrimp (Lehrer et al. 2003).
All these proteins seem fairly resistant to heat, chemical denaturation and proteolysis therefore management of food allergy relies on a strict adherence to an avoidance
diet aiming at the total exclusion of the offending food.
Recent research has shown that the engineering of hypoallergenic variants of fish
parvalbumin and shrimp tropomyosin by site-directed mutagenesis may represent a
candidate approach for specific immunotherapy of seafood allergy (Swoboda et al.
2002, Lehrer et al. 2003, Reese et al. 2005). These studies clearly show that by
modifying the amino acid sequence at specific locations, it was possible to reduce
significantly (in some cases >99%) the reactivity of mutated epitopes.
M.L. Cancela et al.
toxicological evaluation. Firstly, their high throughput nature means that it is possible to analyze multiple tissues in a timely and cost-effective manner. In addition,
DNA amplification is much less time consuming and can easily provide identification of biological contaminants such as microorganisms or viruses. Secondly, by
applying transcriptomics, proteomics and metabolomics the full range of biological
responses from gene expression to cellular functions can be studied.
7.5.4.1 Health Hazards in Seafood
The development and application of DNA-based analytical techniques to ensure
seafood safety is currently the object of intense research efforts. Major hazards in
terms of the safety of seafood products are: toxic compounds (e.g. environmental chemical pollutants, biotoxins), viruses, bacteria and parasites. Nowadays, gene
expression measured by DNA microarrays is believed to provide a more comprehensive, sensitive and characteristic insight into toxicity than typical toxicological
parameters such as morphological changes, altered reproductive capacity or mortality (Steinberg et al. 2008). In recent years, the generation of EST databases for
species important in aquaculture and aquatic toxicology, have resulted in the development of DNA microarray platforms where expression of multiple genes can be
assessed simultaneously, following exposure to environmental pollutants and natural
environmental chemical stressors. Furthermore, expression profiling is an appealing
alternative in ecotoxicological screening, both due to the possibility of monitoring
multiple classical toxicological biomarker genes simultaneously and the possible
discovery of novel biomarkers (for review see Battershill 2005, Heijne et al. 2005,
Brul et al. 2006).
7.5.4.2 Allergenicity in Seafood Products
Seafood allergies are a significant public health concern throughout the world and
although certainly overestimated in the public perception, they are most prevalent
in coastal populations where the consumption and processing of fish and shellfish
are high, such as in Scandinavia and Iberian Peninsula countries. Major seafood
allergens identified are the Ca 2+ -binding proteins, parvalbumin in fish and muscle
tropomyosin (Pen a1) and arginine kinase (Pen a2) in shrimp (Lehrer et al. 2003).
All these proteins seem fairly resistant to heat, chemical denaturation and proteolysis therefore management of food allergy relies on a strict adherence to an avoidance
diet aiming at the total exclusion of the offending food.
Recent research has shown that the engineering of hypoallergenic variants of fish
parvalbumin and shrimp tropomyosin by site-directed mutagenesis may represent a
candidate approach for specific immunotherapy of seafood allergy (Swoboda et al.
2002, Lehrer et al. 2003, Reese et al. 2005). These studies clearly show that by
modifying the amino acid sequence at specific locations, it was possible to reduce
significantly (in some cases >99%) the reactivity of mutated epitopes.