Part C | 18.5
484 Part C Marine Genomics
sediments and are a constant threat to the health of
marine organisms [18.61]. Pollutants accumulating in
coastal and near-shore zones affect marine animals by
altering metabolic and developmental processes and,
consequently, disrupting reproduction, modifying behavior, and decreasing disease resistance [18.55, 62].
Biomonitoring of marine pollution has been extensively
used as a means of determining the extent of pollution. The rationale is that xenobiotic pollutants are
biomagnified and accumulate in marine organisms, especially filter feeding invertebrates, in direct correlation
to the concentration in which they occur in the environment [18.63]. Thus, pollutants can be quantified
in tissue samples from key marine animals, referred
to as sentinel organisms, living in the monitored environment [18.64, 65]. Bivalves are favored as sentinel
organisms, since they are sessile filter feeders capable of accumulating high levels of xenobiotics, and
consequently, they provide temporal and spatial information regarding the extent of contamination [18.64].
Since many biological and abiotic factors have been
found to affect xenobiotic bioaccumulation, biomonitoring programs now include the use of biomarkers,
such as metallothioneins, cytochrome P450, glutathione
transferase, and heat-shock proteins, which specifically
respond to xenobiotics encountered by sentinel organisms [18.63–66]. Even so, effective use of biomolecules
as a means of monitoring marine pollution has its limitations, since their activity, which fluctuates naturally in
response to biotic and abiotic factors, is governed by the
route of chemical exposure (dietary or waterborne), the
extent of bioaccumulation of the xenobiotic and detoxification mechanisms of the sentinel organism [18.64–
66]. Consequently, environmental proteomics or ecotoxicoproteomics is increasingly becoming the biomonitoring tool of choice [18.63, 66].
The advantage of using proteomics for biomonitoring is that it provides information regarding the
response of the entire proteome to the pollutant, thus
identifying groups of proteins that respond strongly and
specifically to particular pollutants [18.64]. In addition to establishing a protein expression signature (PES)
specific to a particular xenobiotic, proteomics provides
additional information that may elucidate the molecular processes and pathways that detoxify and catabolize
particular pollutants [18.63, 65–67].
Ecotoxicoproteomics is already proving invaluable
as a biomonitoring tool. Liu et al. [18.63] used a proteomic approach to investigate the effect of cadmium
(Cd) on bioaccumulation of other heavy metals in four
bivalves: the scallop Chlamys nobilis, the clam Ruditapes philippinarum, the mussel Perna viridis, and
the oyster Saccostrea cucullata. Cd, which pollutes the
marine environment through activities such as mining, mineral ore refining, electro-plating and fertilizers,
is highly toxic to marine organisms as it results in
oxidative damage by ROS and disrupts physiological
processes involved with essential metal ions such as
Ca
2C [18.66]. Although they found that exposure to
cadmium influenced the bioaccumulation of other trace
metals, Cd had little effect on the bivalve proteomes,
and the identified proteins were insufficient to explain
the observed disruption of trace element metabolism.
Nevertheless, the PES could distinguish between clams
and mussels that had accumulated different concentrations of Cd, and even though a PES for oysters and
scallops was not obtained, the strong up-regulation of
galectin in Cd-exposed oysters suggests that this protein has potential as a novel biomarker in environmental
monitoring [18.63].
In another study, Leung et al. [18.66] investigated
the proteomic response in hepatopancreas and adductor muscle tissue sampled from the green lipped mussel
Perna viridis after a two-week exposure to Cd and hydrogen peroxide (H 2 O 2 ), a persistent ROS linked to
anthropogenic pollution such as dissolved organic matter and sewage disposal. Cd and H 2 O 2 resulted in two
unique sets of tissue-specific PESs and revealed that
the former xenobiotic was responsible for endoplasmic reticulum and oxidative stress in the hepatopancreas and disrupted Ca
2C homeostasis in adductor
muscle [18.66].
A study investigating changes in the proteome of
the hepatopancreas of the blue mussel Mytilus edulis
sampled from four sites in the vicinity of Gothenburg
harbor, Sweden, generated a PES composed of 13 proteins that allowed the pollution-free site (Fjällbacka)
to be distinguished from the 3 polluted sites [18.65].
Principal component analysis (PCA) and hierarchical
clustering validated the discriminatory power of the
PES and provided a spatial gradient from the polluted
source.
Not only has proteomics proved invaluable for the
discovery ofbiomarkers for monitoring environmental
pollution, the technology has also been successfully
used to investigate the effects of environmental pollutants on marine organisms, both in terms of their
health and the health of seafood consumers. Mercury
is a heavy metal pollutant that poses a danger worldwide as a consequence of its neurotoxic effect on fish
and human brain tissue [18.68]. A report recently released by the Biodiversity Research Institute’s Center
484 Part C Marine Genomics
sediments and are a constant threat to the health of
marine organisms [18.61]. Pollutants accumulating in
coastal and near-shore zones affect marine animals by
altering metabolic and developmental processes and,
consequently, disrupting reproduction, modifying behavior, and decreasing disease resistance [18.55, 62].
Biomonitoring of marine pollution has been extensively
used as a means of determining the extent of pollution. The rationale is that xenobiotic pollutants are
biomagnified and accumulate in marine organisms, especially filter feeding invertebrates, in direct correlation
to the concentration in which they occur in the environment [18.63]. Thus, pollutants can be quantified
in tissue samples from key marine animals, referred
to as sentinel organisms, living in the monitored environment [18.64, 65]. Bivalves are favored as sentinel
organisms, since they are sessile filter feeders capable of accumulating high levels of xenobiotics, and
consequently, they provide temporal and spatial information regarding the extent of contamination [18.64].
Since many biological and abiotic factors have been
found to affect xenobiotic bioaccumulation, biomonitoring programs now include the use of biomarkers,
such as metallothioneins, cytochrome P450, glutathione
transferase, and heat-shock proteins, which specifically
respond to xenobiotics encountered by sentinel organisms [18.63–66]. Even so, effective use of biomolecules
as a means of monitoring marine pollution has its limitations, since their activity, which fluctuates naturally in
response to biotic and abiotic factors, is governed by the
route of chemical exposure (dietary or waterborne), the
extent of bioaccumulation of the xenobiotic and detoxification mechanisms of the sentinel organism [18.64–
66]. Consequently, environmental proteomics or ecotoxicoproteomics is increasingly becoming the biomonitoring tool of choice [18.63, 66].
The advantage of using proteomics for biomonitoring is that it provides information regarding the
response of the entire proteome to the pollutant, thus
identifying groups of proteins that respond strongly and
specifically to particular pollutants [18.64]. In addition to establishing a protein expression signature (PES)
specific to a particular xenobiotic, proteomics provides
additional information that may elucidate the molecular processes and pathways that detoxify and catabolize
particular pollutants [18.63, 65–67].
Ecotoxicoproteomics is already proving invaluable
as a biomonitoring tool. Liu et al. [18.63] used a proteomic approach to investigate the effect of cadmium
(Cd) on bioaccumulation of other heavy metals in four
bivalves: the scallop Chlamys nobilis, the clam Ruditapes philippinarum, the mussel Perna viridis, and
the oyster Saccostrea cucullata. Cd, which pollutes the
marine environment through activities such as mining, mineral ore refining, electro-plating and fertilizers,
is highly toxic to marine organisms as it results in
oxidative damage by ROS and disrupts physiological
processes involved with essential metal ions such as
Ca
2C [18.66]. Although they found that exposure to
cadmium influenced the bioaccumulation of other trace
metals, Cd had little effect on the bivalve proteomes,
and the identified proteins were insufficient to explain
the observed disruption of trace element metabolism.
Nevertheless, the PES could distinguish between clams
and mussels that had accumulated different concentrations of Cd, and even though a PES for oysters and
scallops was not obtained, the strong up-regulation of
galectin in Cd-exposed oysters suggests that this protein has potential as a novel biomarker in environmental
monitoring [18.63].
In another study, Leung et al. [18.66] investigated
the proteomic response in hepatopancreas and adductor muscle tissue sampled from the green lipped mussel
Perna viridis after a two-week exposure to Cd and hydrogen peroxide (H 2 O 2 ), a persistent ROS linked to
anthropogenic pollution such as dissolved organic matter and sewage disposal. Cd and H 2 O 2 resulted in two
unique sets of tissue-specific PESs and revealed that
the former xenobiotic was responsible for endoplasmic reticulum and oxidative stress in the hepatopancreas and disrupted Ca
2C homeostasis in adductor
muscle [18.66].
A study investigating changes in the proteome of
the hepatopancreas of the blue mussel Mytilus edulis
sampled from four sites in the vicinity of Gothenburg
harbor, Sweden, generated a PES composed of 13 proteins that allowed the pollution-free site (Fjällbacka)
to be distinguished from the 3 polluted sites [18.65].
Principal component analysis (PCA) and hierarchical
clustering validated the discriminatory power of the
PES and provided a spatial gradient from the polluted
source.
Not only has proteomics proved invaluable for the
discovery ofbiomarkers for monitoring environmental
pollution, the technology has also been successfully
used to investigate the effects of environmental pollutants on marine organisms, both in terms of their
health and the health of seafood consumers. Mercury
is a heavy metal pollutant that poses a danger worldwide as a consequence of its neurotoxic effect on fish
and human brain tissue [18.68]. A report recently released by the Biodiversity Research Institute’s Center