Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp) |
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Production of cultivated shrimp
has been a major industry for Thailand from
the late 1980’s. The industry employs
about
300,000 people nationwide and has export
earnings of about 100 billion baht (about
2 billion US dollars) per year. Thus,
Thailand has become a world leader in the
production of premium, value-added shrimp
products and shrimp seed. To maintain this
leadership, Thailand must develop and train
specialists to carry out relevant research
and provide continuous industry support. |
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The
Center of Excellence for Shrimp Molecular
Biology and Biotechnology (abbreviated as
Centex Shrimp) is a multidisciplinary laboratory
formed in October 2001 by amalgamation
of research laboratories from the Departments
of Anatomy, Biochemistry and Biotechnology
of the Faculty of Science, jointly supported
by the Faculty of Science, Mahidol University
and the National Center for Genetic Engineering
and Biotechnology (BIOTEC). Its mission
is “Premier science for premium shrimp”
and its vision is that Thailand in 2012
will lead the world in producing the highest
quality shrimp products without negative
environmental impact. Centex strategy for
achieving this goal is 1) to maintain its
position as a national
and regional focus for research and training
in molecular biology and biotechnology for
shrimp production, 2) to serve as a coordination
center whereby Mahidol University can cooperate
with BIOTEC and other national and international
institutions on shrimp research and 3) to
operate in close consultation with the Thai
shrimp industry so that Centex work is both
academically sound and relevant to shrimp
industry needs. |
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Current priorities are broodstock
development, and disease diagnosis and control.
The six main areas of related research interest
are molecular study of shrimp pathogens
including viruses, bacteria and parasites;
development of diagnostic probes and kits
for shrimp diseases; research on shrimp
humoral and cellular defense mechanisms;
shrimp genome analysis; shrimp nutritional
research related to reproduction; and development
and improvement of domesticated and specific
pathogen-free (SPF) black tiger shrimp stocks.
Although hard to predict, future needs may
shift to such areas as genetic improvement
of domesticated stocks, improvement in shrimp
production efficiency (e.g., reduced mortality
at all stages of rearing) and support for
introduction of alternative species. Being
a “firehouse” is also an important
Centex function. Centex shrimp is a storehouse
of information, technology and expertise
in shrimp disease diagnosis and control
and can respond quickly to assist the shrimp
industry in stopping disease outbreaks,
such as the exotic Taura syndrome virus
(TSV), which came from the Americas via
importation of infected white shrimp (P.
vannamei) stocks. Centex Shrimp is also
prepared for the possible emergence of other
viruses. |
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| Molecular study and
diagnosis of shrimp pathogens including
viruses, bacteria and parasites |
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Controlling
disease is a high priority for the shrimp
industry. Centex Shrimp has focused on characterization
of causative viruses, to enable development
of rapid diagnostic probes. However, we
also work on bacteria and parasites. Since
2002, we have studied not only the diseases
of the black tiger shrimp (Penaeus monodon),
but also the American white shrimp (Penaeus
vannamei). Deadly viruses include white-spot
syndrome virus (WSSV) and yellow-head virus
(YHV) for all cultured shrimp, hepatopancreatic
parvovirus (HPV) and monodon baculovirus
(MBV) for black tiger shrimp, and Taura
syndrome virus (TSV) and infectious hypodermal
and haematopoeitic virus (IHHNV) for the
American white shrimp. DNA diagnostic procedures
for several of these (WSSV, YHV and HPV)
have been developed by our group and the
technology has been licensed to the Shrimp
Biotechnology Business unit (SBBU) of BIOTEC
under the Ezee Gene brand. We have also
developed molecular diagnostic methods for
the bacterium Vibrio parahaemolyticus and
for two species of microsporidians. Detailed
research is also being carried out on the
total genome of YHV and expression of its
structural proteins, with the view of using
the expressed proteins to carry out functional
studies and to develop diagnostic kits and
“vaccines”. |
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| Shrimp genome analysis |
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| Centex Shrimp research on
shrimp genome analysis focuses on construction
of EST libraries from normal and pathogen
challenged shrimp in collaboration with
Dr. Anchalee Tassanakajon, at Chulalongkorn
University. Ongoing studies in functional
genomics and proteomics with selected genes
are helping us to understand shrimp defense
mechanisms and devise new methods of disease
control. The EST libraries will also help
in the construction of a genetic map for
P. monodon that will be applied in programs
for genetic improvement of domesticated
shrimp stocks. Genetic mapping work is being
done in collaboration with research groups
in Australia, Japan and Taiwan. |
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| Shrimp humoral and
cellular defense mechanisms |
Shrimp viral infections are characterized
by the general lack of an inflammatory response.
Epizootics by newly introduced viral pathogens
follow a pattern of initial, wide spread,
catastrophic crop losses and then, within
a year or so, sporadic crop losses even
though
the pathogen is widespread in persistently
infected shrimp that show little or no mortality.
Understanding the phenomenon may help us
to develop new methods of prevention and
therapy. Centex Shrimp scientists have proposed
a radically new working concept called “active
viral accommodation” to explain this
adaptation. Test results suggest that shrimp
actively accommodate viral pathogens as
persistent infections that help to reduce
disease severity, possibly by inactivating
triggers for viral induced apoptosis (i.e.,
programmed cell death).
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| Shrimp nutritional
research |
| Centex Shrimp’s interest
in shrimp nutrition focuses on broodstock,
particularly for maturation and reproduction
diets. It is well-known that best results
for egg and larval production in broodstock
shrimp can be obtained only by using live
polychaete worms. To avoid problems with
disease transfer from captured polychaetes,
we have developed methods for rearing SPF
polychaetes for safe feeding of broodstock
and are trying to discover why live polychaetes
are so necessary for good shrimp reproduction.
We are also interested in probiotic microbes,
immunostimulants, and the effect of nutrition
and stress on disease. |
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| Shrimp reproduction. |
 Aside
from broodstock nutrition, we are trying
to better understand the shrimp reproductive
process, with the aim of increasing efficiency
of larval production, as well as larval
survival and quality in shrimp hatcheries.
For example, our recent studies have revealed
that egg maturation is very fast in P. monodon
and that the interval available for fertilization
is very, very short after egg release (spawning).
In addition, we found that sperm stored
in the female theylicum undergoes a maturation
process, essential to obtain high fertilization
rates. We hope that a better understanding
will allow better control over the reproductive
process, and possible cryopreservation of
eggs and sperm, as well as in vitro fertilization. |
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| Development and improvement
of domesticated, specific pathogen-free
(SPF) black tiger shrimp |
Increasing
usage of wild P. monodon broodstock to produce
postlarvae (PL) in hatcheries in Thailand
and worldwide has led to a reduction in
the number and quality of captured wild
broodstock available in Thailand. Prices
have risen steeply and this has increased
the cost
of hatchery operation and the price of post
larvae for farmers. The captured wild broodstock
are also highly variable in terms of the
seed quality they produce. The best solution
to these problems would be domestication
of P. monodon. Centex Shrimp is closely
allied to the national Shrimp Improvement
and Breeding Center (SIBC) of BIOTEC located
at Chaiya in Srathani Province in southern
Thailand and the nearby Shrimp Quarantine
and Broodstock and Larval Development Research
Center at Walailuk University in Nakornsrithammarat
Province. Centex Shrimp assists these enterprises
in biotechnological aspects of improving
pathogen control, reproductive performance,
and methods for selection of economically
important traits. |
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| Training |
| Centex Shrimp has an active
post-graduate training program with 15-20
M.Sc. and Ph.D. students and up to 5 post-doctoral
fellows. It also accepts a few undergraduate
students for senior projects each year.
In addition, it offers a yearly regional
training course on shrimp biology and pathology
and occasional courses on specialized topics
according to demand. For example, it recently
sponsored together with BIOTEC a specialist
course on shrimp immunology for both local
and international participants. In cooperation
with SBBU, it also provides consultants
and training at the request of the Thai
shrimp industry in the areas of disease
diagnosis, disease control and broodstock
development |
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| Awards |
| The three lead scientists
Vichai Boonsaeng, Tim Flegel and Boonsirm
Withyachumnarnkul were awarded the Toray
Science Foundation Award in 2000 for their
work on shrimp viral disease diagnosis and
control, as well as the Outstanding Technology
Group Award in 2003 in recognition for development
of practical diagnostic reagents and tools
for the black tiger shrimp industry. Wansika
Kiatpathomchai and Dr. Kallaya Sritunyalucksana
received UNESCO-L’Oreal Women of Science
Awards in 2005 and 2007. |
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| Collaboration |
| Centex Shrimp attempts to
work with other scientists both in Thailand
and aboard that share interests in disease
diagnosis and control and development of
domesticated broodstock. A number of mutual
benefits and joint publications have resulted.
In Thailand, links include Chulalongkorn
University on shrimp genetics, Srinakharinwirot
University on diagnostic tool development,
Rangsit University on pathogen isolation,
characterization and diagnosis, Prince of
Songkhla University on disease diagnosis
and control, the Thai Department of Fisheries
on disease control and shrimp domestication,
and Mae Jo University on shrimp apoptotic
genes. Overseas collaborators include the
National University of Taiwan, CSIRO Livestock
Industries, Australia, University of Arizona,
University of Uppsala, Sweden, James Cook
University, Australia, and the Oceanic Institute,
Hawaii. These external collaborations sometimes
involve student and scientist exchanges
and have led to a number of joint publications
in international scientific journals. |
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| Sample publications
2007 |
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1. |
Molthathong S, Rojtinnakorn
J, Senapin S, Flegel TW (2007) Hepatopancreatic
nuclease of black tiger shrimp Penaeus monodon
unlikely to be involved in viral triggered
apoptosis. Fish & Shellfish Immunology
22:617-627 |
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| 2. |
Flegel TW (2007) The right to refuse revision
in the genus Penaeus. Aquaculture 264:2-8 |
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| 3. |
Sithigorngul W, Rukpratanporn S, Sittidilokratna
N, Pecharaburanin N, Longyant S, Chaivisuthangkura
P, Sithigorngul P (2007) A convenient immunochromatographic
test strip for rapid diagnosis of yellow
head virus infection in shrimp. Journal
of Virological Methods 140:193-199 |
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| 4. |
Flegel TW (2007) Update on viral accommodation,
a model for host-viral interaction in shrimp
and other arthropods. Developmental &
Comparative Immunology 31:217-231 |
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| 5. |
Senapin S, Phewsaiya K, Briggs M, Flegel
TW (2007) Outbreaks of infectious myonecrosis
virus (IMNV) in Indonesia confirmed by genome
sequencing and use of an alternative RT-PCR
detection method. Aquaculture 266:32-38 |
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| 6. |
Sriphaijit T, Senapin S (2007) High expression
of a novel leucine-rich repeat protein in
hemocytes and the lymphoid organ of the
black tiger shrimp Penaeus monodon. Fish
& Shellfish Immunology 22:264-271 |
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| 7. |
Sriphaijit T, Flegel TW, Senapin S Characterization
of a shrimp serine protease homolog, a binding
protein of yellow head virus. Developmental
& Comparative Immunology In Press, Corrected Proof: 2786 |
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| 8. |
Sangsuriya P, Rojtinnakorn J, Senapin
S, Flegel TW Characterization and tissue
expression of apoptosis-related ALG-2 interacting
protein Alix/AIP1 from the black tiger shrimp
Penaeus monodon. Fish & Shellfish Immunology.
In Press, Corrected Proof |
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| Contact address: |
Centex Shrimp, Chalerm Phrakiat
Building
Faculty of Science, Mahidol University
Rama VI Road, Bangkok 10400, Thailand
Tel: (66-2) 247-5870-2
Fax: (66-2) 247 7051
e-mail: tetlt@mahidol.ac.th |
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