Proteomics: Applications and Advances 18.4 Aquaculture 481
Part C | 18.4
during reproductive development of the Eastern oyster Crassostrea virginica. SELDI-TOF-MS combines
array technology, which allows high resolution separation of proteins from complex mixtures on a chip, and
mass spectrometry [18.47]. SELDI-TOF-MS is more
sensitive than traditional MS and allows rapid sample
throughput [18.46, 47]. The study identified 62 peptides
associated with oyster reproduction and, consequently,
was able to categorize individual broodstock animals
into one of five groups: undifferentiated, female developing, female ripe, male developing, and male ripe with
an accuracy of 98:8% [18.46].
Besides ensuring that broodstock animals are ripe
for spawning, the quality of the eggs produced is also
important in terms of ensuring that viable progeny
are consistently produced in the hatchery. Corporeau
et al. [18.48] employed a proteomic approach to identify abundant proteins linked to oocyte quality in the
Pacific oyster Crassostrea gigas, rather than measuring oocyte diameter or total lipid content. Ten proteins were found to be up-regulated in low quality
oocytes, which included vitellogenin-breakdown products and metabolic enzymes, while six up-regulated
proteins from high quality oocytes included the chaperone heat-shock cognate protein 70 (HSC70) and cellcycle control proteins [18.48]. The authors of the study
postulated that increased levels of HSC70 may ensure
improved protein folding in two-cell embryos and enhanced protection of oocytes and early embryos directly
exposed to environmental stresses such as oxidative
stress and temperature fluctuations. Likewise, up-regulation of the putative cell-cycle control protein 14-3-3
" may be important in oocyte cell-cycle control and
enhanced protection of embryos, while proliferative
cell nuclear antigen (PCNA) has been associated with
processivity of deoxyribonucleic acid (DNA) synthesis
during early development [18.48].
18.4.3 Animal Production
To ensure that an aquaculture enterprise remains profitable, it is important that the growth rate of the animals
is optimized so that the time they spend on the farm
is minimized in order to keep production costs relatively low and reduce the risk of loss to stress and
disease. Maslinic acid (MA, 2˛,3ˇ-dihydroxyolean12-en-28-oic acid) has been found to improve the
growth rate of rainbow trout by increasing hepatic
protein-turnover rates, elevating the hyperplasia level
and augmenting liver glycogen content [18.49]. Indeed,
Fernández-Navarro et al. [18.50] found that trout fed
a diet supplemented with 250 mg MA per kg feed for
225 days exhibited a 29% increase in weight in comparison to control animals.
Since Sparus aurata is an economically valuable
marine species for fish farming, the effect of MA supplementation on the liver proteome of this fish was
tested under farm conditions [18.49]. Two-dimensional
electrophoresis of total protein samples from the experimental and control groups showed that 49 protein
spots were differentially regulated in fish fed the MAsupplemented diet for 210 days. MALDI-TOF/TOF
analysis allowed unambiguous identification of 19 different proteins that play a role in metabolism of
glucose (phosphoglucomutase 1, phosphoglucose isomerase, and S-adenosyl methionine-dependent methyltransferase class 1), lipids (17ˇ-hydroxysteroid dehydrogenase type 4 (HSDH4)), amino acids (fumarylacetoacetate hydrolase, 4-hydroxy-phenylpyruvic dioxygenase, methylmalonate-semialdehyde dehydrogenase),
and purines (urate oxidase), as well as detoxification and metabolism of xenobiotics (aldehyde dehydrogenase), oxidative stress (catalase and 6-phosphogluconate dehydrogenase), immune system (lysozyme
chain A), protein synthesis (elongation factor 2 of
eukaryotic protein synthesis), protein folding (Hsp60,
58 kDa glucose-regulated protein), signalling (kinase
suppressor of Ras1 (KSR1)), and cytoskeleton formation (cytokeratin E7, intermediate filament proteins,
KERII).
Fernández-Navarro et al. [18.50] proposed a signaling mechanism to explain how MA affected the
liver of gilthead sea bream at the molecular and cellular level. The interaction between MA and its receptors, modulated by increased HDSH4, inhibits KSR1
expression and consequently activates the signal-transduction pathway mediated by Ras. This affects cellular functions such as glucose and other metabolism,
detoxification and xenobiotic metabolism, oxidative
stress, amino acid catabolism, nonspecific immune system, purine catabolism, protein synthesis and folding,
and cytoskeleton proteins, leading to stimulation of
growth, protein-turnover rates, total content of deoxyribonucleic acid (DNA), ribonucleic acid (RNA),
and proteins, nicotinamide adenine dinucleotide phosphate (NADPH)-production systems, and antioxidant
defence.
A similar approach was used to assess the effect of the glutamine precursor ˛-ketoglutarate (AKG),
used as a dietary supplement, on the pituitary proteome of gilt-head sea bream [18.51]. The rationale
for the study was based on the fact that pituitary hor-
Part C | 18.4
during reproductive development of the Eastern oyster Crassostrea virginica. SELDI-TOF-MS combines
array technology, which allows high resolution separation of proteins from complex mixtures on a chip, and
mass spectrometry [18.47]. SELDI-TOF-MS is more
sensitive than traditional MS and allows rapid sample
throughput [18.46, 47]. The study identified 62 peptides
associated with oyster reproduction and, consequently,
was able to categorize individual broodstock animals
into one of five groups: undifferentiated, female developing, female ripe, male developing, and male ripe with
an accuracy of 98:8% [18.46].
Besides ensuring that broodstock animals are ripe
for spawning, the quality of the eggs produced is also
important in terms of ensuring that viable progeny
are consistently produced in the hatchery. Corporeau
et al. [18.48] employed a proteomic approach to identify abundant proteins linked to oocyte quality in the
Pacific oyster Crassostrea gigas, rather than measuring oocyte diameter or total lipid content. Ten proteins were found to be up-regulated in low quality
oocytes, which included vitellogenin-breakdown products and metabolic enzymes, while six up-regulated
proteins from high quality oocytes included the chaperone heat-shock cognate protein 70 (HSC70) and cellcycle control proteins [18.48]. The authors of the study
postulated that increased levels of HSC70 may ensure
improved protein folding in two-cell embryos and enhanced protection of oocytes and early embryos directly
exposed to environmental stresses such as oxidative
stress and temperature fluctuations. Likewise, up-regulation of the putative cell-cycle control protein 14-3-3
" may be important in oocyte cell-cycle control and
enhanced protection of embryos, while proliferative
cell nuclear antigen (PCNA) has been associated with
processivity of deoxyribonucleic acid (DNA) synthesis
during early development [18.48].
18.4.3 Animal Production
To ensure that an aquaculture enterprise remains profitable, it is important that the growth rate of the animals
is optimized so that the time they spend on the farm
is minimized in order to keep production costs relatively low and reduce the risk of loss to stress and
disease. Maslinic acid (MA, 2˛,3ˇ-dihydroxyolean12-en-28-oic acid) has been found to improve the
growth rate of rainbow trout by increasing hepatic
protein-turnover rates, elevating the hyperplasia level
and augmenting liver glycogen content [18.49]. Indeed,
Fernández-Navarro et al. [18.50] found that trout fed
a diet supplemented with 250 mg MA per kg feed for
225 days exhibited a 29% increase in weight in comparison to control animals.
Since Sparus aurata is an economically valuable
marine species for fish farming, the effect of MA supplementation on the liver proteome of this fish was
tested under farm conditions [18.49]. Two-dimensional
electrophoresis of total protein samples from the experimental and control groups showed that 49 protein
spots were differentially regulated in fish fed the MAsupplemented diet for 210 days. MALDI-TOF/TOF
analysis allowed unambiguous identification of 19 different proteins that play a role in metabolism of
glucose (phosphoglucomutase 1, phosphoglucose isomerase, and S-adenosyl methionine-dependent methyltransferase class 1), lipids (17ˇ-hydroxysteroid dehydrogenase type 4 (HSDH4)), amino acids (fumarylacetoacetate hydrolase, 4-hydroxy-phenylpyruvic dioxygenase, methylmalonate-semialdehyde dehydrogenase),
and purines (urate oxidase), as well as detoxification and metabolism of xenobiotics (aldehyde dehydrogenase), oxidative stress (catalase and 6-phosphogluconate dehydrogenase), immune system (lysozyme
chain A), protein synthesis (elongation factor 2 of
eukaryotic protein synthesis), protein folding (Hsp60,
58 kDa glucose-regulated protein), signalling (kinase
suppressor of Ras1 (KSR1)), and cytoskeleton formation (cytokeratin E7, intermediate filament proteins,
KERII).
Fernández-Navarro et al. [18.50] proposed a signaling mechanism to explain how MA affected the
liver of gilthead sea bream at the molecular and cellular level. The interaction between MA and its receptors, modulated by increased HDSH4, inhibits KSR1
expression and consequently activates the signal-transduction pathway mediated by Ras. This affects cellular functions such as glucose and other metabolism,
detoxification and xenobiotic metabolism, oxidative
stress, amino acid catabolism, nonspecific immune system, purine catabolism, protein synthesis and folding,
and cytoskeleton proteins, leading to stimulation of
growth, protein-turnover rates, total content of deoxyribonucleic acid (DNA), ribonucleic acid (RNA),
and proteins, nicotinamide adenine dinucleotide phosphate (NADPH)-production systems, and antioxidant
defence.
A similar approach was used to assess the effect of the glutamine precursor ˛-ketoglutarate (AKG),
used as a dietary supplement, on the pituitary proteome of gilt-head sea bream [18.51]. The rationale
for the study was based on the fact that pituitary hor-