Growth hormone gene transfer in common carp
Abstract
The first successful case of transgenic fish was achieved in 1984. It is in a model system that the integration and expression of recombinant human growth hormone (hGH) in host red common carp (Cyprinus carpio, red var.) have been thoroughly studied. Recently, the integration sites have been recovered and characterized. Compared with non-transgenic peers, hGH-transgenic fish are prior in dietary utilization and growth performance. In view of bio-safety and bio-ethics, an “all-fish” construct CAgcGH, grass carp growth hormone fused with common carp β-actin promoter, has been generated and transferred into Yellow River carp (C. carpio, local strain in Yellow River) fertilized eggs. Under middle-scale trial, CAgcGH-transgenics show higher growth rate and food conversion efficiency than the controls, which is consistent to laboratory findings. To avoid the potential impact of transgenic fish on the environment, a sterile strain of transgenic triploid fish has been successfully produced. The “all-fish” transgenic common carp is also approved safe enough as daily food, according to a test based on the pathological principles of new medicines issued by the Ministry of Health of China. The “all-fish” transgenic common carp with growth enhancement is now ready for market, but looking for governmental authorization.
Review
Growth hormone gene transfer in common carp
Gang Wu
1
,Yonghua Sun
1
, Zuoyan Zhu *
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
Received 28 November 2002; accepted 11 June 2003
Abstract
The first successful case of transgenic fish was achieved in 1984. It is in a model system that the integration and expression of recombinant
human growth hormone (hGH) in host red common carp (Cyprinus carpio, red var.) have been thoroughly studied. Recently, the integration
sites have been recovered and characterized. Compared with non-transgenic peers, hGH-transgenic fish are prior in dietary utilization and
growth performance. In view of bio-safety and bio-ethics, an “all-fish” construct CAgcGH, grass carp growth hormone fused with common
carp b-actin promoter, has been generated and transferred intoYellow River carp (C. carpio, local strain inYellow River) fertilized eggs. Under
middle-scale trial, CAgcGH-transgenics show higher growth rate and food conversion efficiency than the controls, which is consistent to
laboratory findings. To avoid the potential impact of transgenic fish on the environment, a sterile strain of transgenic triploid fish has been
successfully produced. The “all-fish” transgenic common carp is also approved safe enough as daily food, according to a test based on the
pathological principles of new medicines issued by the Ministry of Health of China. The “all-fish” transgenic common carp with growth
enhancement is now ready for market, but looking for governmental authorization.
© 2003 Éditions scientifiques et médicales Elsevier SAS and Ifremer/IRD/Inra/Cemagref. All rights reserved.
Résumé
Transfert du gène de l’hormone de croissance chez la carpe commune. Le premier cas de poisson transgénique a été réalisé avec
succès en 1984. L’intégration et l’expression de l’hormone de croissance humaine recombinante (hGH) ont été étudiées chez la carpe
commune var. rouge (Cyprinus carpio, red var.) en tant que système modèle. Récemment, les sites d’intégration ont été trouvés et caractérisés.
Comparées aux carpes non-transgéniques, les carpes transgéniques-hGH ont des performances supérieures d’assimilation nutritionnelle et de
croissance. En vue de sécurité biologique et de bio-éthique, un promoteur, de b-actine de la carpe commune, fusionné avec l’hormone de
croissance de la carpe Ctenopharyngodon idellus, a été généré en « all-fish » CAgcGH et transféré dans des œufs fécondés d’une souche locale
de la carpe du fleuve Jaune. Un essai à moyenne échelle de transgéniques-CAgcGH montre des taux de croissance et de conversion alimentaire
plus élevés que les témoins, ce qui correspond aux résultats obtenus en laboratoire. Afin d’éviter un impact possible des poissons transgéniques
sur l’environnement, une souche stérile de poisson triploïde transgénique a été obtenue avec succès. Les carpes « all-fish » transgéniques de la
carpe commune sont aussi reconnues comme suffisamment propres à la consommation, d’après un test fondé sur des principes pathologiques
des nouvelles médecines du ministère de la santé de la Chine. La carpe transgénique à croissance accélérée est désormais prête pour le marché
mais en attente d’autorisation gouvernementale.
© 2003 Éditions scientifiques et médicales Elsevier SAS and Ifremer/IRD/Inra/Cemagref. All rights reserved.
Keywords: Growth hormone; Gene transfer; Growth; Safety; Common carp
1. Introduction
Fishes, widely cultured all over the world, have served
people as one of the most important food supplies for a
million or so years. Fish culture, moreover, is one of the
earliest activities of human civilization. The first record of
fish culture can be dated back to 2500 years ago. In the
Handbook of Fish Culture, the author Fan Li described the
domestication and cultivation of common carp (Cyprinus
carpio) in ponds. Ever since, common carp has become one
of the most important farmed species in aquaculture.
The techniques of fish culture have been greatly devel-
oped along with civilization over the past thousands of years.
However, the aquatic productivity is subject to the natural
* Corresponding author.
E-mail address: zyzhu@ihb.ac.cn (Z. Zhu).
1
These authors contribute equally to this article.
Aquat. Living Resour. 16 (2003) 416–420
www.elsevier.com/locate/aquliv
© 2003 Éditions scientifiques et médicales Elsevier SAS and Infremer/IRD/Inra/Cemagref. All rights reserved.
doi:10.1016/S0990-7440(03)00087-1
performance of the breeding species. Population explosion
and overfishing in the past decades has made it impossible to
meet the increasing demands on fish protein through tradi-
tional aquaculture (FAO, 2000). In order to improve the
qualities and quantities of important farmed fishes, it is
necessary to develop new breeding techniques, other than
those methods that rely on classical genetic selection and
hybridization.
Around the late 1970s, Chinese investigators who had a
long career on fish nuclear transplantation initiated a study of
“total DNA” transferred mud carp (Cirrhina molitorella). In
this study, the total DNA of common carp, a species of fish
that could survive cold winter, was transferred into the fertil-
ized eggs of mud carp, a tropical species. About 8% of the
total DNA transferred mud carp showed improvement on
cold-resistance (Zhu and Huang, unpublished data). In the
early 1980s, with the advancement of molecular cloning and
micromanipulation, it was possible to isolate a single gene
coding a unique protein and introduce the gene into the
fertilized eggs of vertebrate (Bending, 1981). The newly
developed biotechnology gave birth to the well-known trans-
genic “super mouse” (Palmiter et al., 1982). Two or 3 years
later, a recombinant human growth hormone gene (hGH)was
successfully transferred into the fertilized eggs of goldfish
(Zhu et al., 1985) and loach (Zhu et al., 1986), which led to
the birth of “fast-growing” transgenic fish. For application
purpose, an “all-fish” recombinant growth hormone (GH)
was subsequently constructed and transferred into common
carp (Zhu, 1992a; Wang et al., 2001). After rigid safety
evaluation, “all-fish” GH-transgenic common carp has been
proved a successful example for modern aquaculture (Wang
et al., 2001; Zhu, 2000).
In addition to produce GH-transgenic fish for growth
enhancement, many investigators have attempted to produce
transgenic fish with other valuable traits. For example, anti-
freeze proteins gene (AFP) was used to achieve freeze-
resistant salmon (Hew et al., 1992) and cold-tolerance gold-
fish (Wang et al., 1995); lysozyme coding sequence was
introduced into Atlantic salmon to gain disease resistance
(Hew et al., 1995), infectious hematopoietic necrosis virus
proteins coding sequences into rainbow trout eggs as DNA
vaccination (Anderson et al., 1996), and human lactoferrin
gene (hLF) into grass carp to promote the resistance to grass
carp hemorrhage virus (GCHV) (Zhong et al., 2002). Never-
theless, GH-transgenic fish with growth enhancement is so
far the one that has drawn the most attention, that has been
the most thoroughly investigated, and that is also the most
likely to be on the market in the near future. In the following
paragraphs, we will briefly review the study of GH-
transgenic common carp, especially the work conducted in
our laboratory.
2. A model study of transgenic fish
In the early 1980s, a few recombinant genes relevant to
morphology were available. One of them was MThGH con-
struct from Dr. D.H. Hamer (Pavlakis and Hamer, 1983),
hGH under the control of mouse metallothionein-1 (MT-1)
promoter. Subsequently, MThGH was microinjected into the
fertilized eggs of goldfish and a batch of fast growing trans-
genic fish was produced (Zhu et al., 1985). Other than the
technique of microinjection that needs skillful manipulators,
a variety of more convenient approaches, including elec-
troporated and sperm-mediated methods, have been success-
fully employed for generation of transgenic fish (Inoue et al.,
1990; Khoo et al., 1992; Xie et al., 1993; Synonds et al.,
1994; Li et al., 1996; Zhong et al., 2002).
A study focused on the behavior of the foreign pMThGH
gene during the embryogenesis of host common carp had
been carried out (Zhu et al., 1989). It was found that the
foreign gene endured a dynamic process during this course,
including replication, degradation, concatenation and inte-
gration. The replication of the foreign gene started immedi-
ately once introduced into the fertilized eggs, and the stron-
gest signal of replication occurred from late blastula to early
neurula. Concatamers were the dominant form of foreign
gene when the embryo developed from multi-cell stage to
late gastrula stage. The integration of foreign gene was sup-
posed to take place from the early stage and last for a long
time course, which resulted in the transgenic mosaicism, i.e.
the integrated transgenes were distributed in different tissues
and organs of the transgenic fish along with the embryogen-
esis. It was obvious that only those transgenes integrated into
the genome of germline could be transmitted to the offspring
via sexual reproduction. The transcription of the foreign gene
could be observed at the late-gastrula stage and radio immu-
nity analysis revealed that different individuals had different
levels of transgene expression. As a result of the expression
of MThGH, some transgenics gained significant improve-
ment on growth performance; whereas, some were smaller
than the controls, and even showed morphological deformi-
ties. According to the positional effects related to the expres-
sion and function of transgene, the manners of transgene
integration were divided into three categories: functional
integration, silent integration and toxic integration. Com-
pared with silent integration that does not show any effect
and toxic integration that blocks the normal development,
only functional integration results in the normal expression
of hGH and growth enhanced transgenic fish (Zhu et al.,
1989; Wei et al., 1992). Therefore, it is of great necessity to
set up transgenic lines carrying functional integration for
aquaculture purpose. Hybridization between transgenics and
non-transgenics has shown to be an efficient way to attain
this goal (Hew et al., 1992; Lin et al., 1994).
When transgenic male was hybridized against non-
transgenic female, 72–88% offspring were transgene carri-
ers. The results suggested that there were two to three inte-
gration sites in the genome of each germ cell according to
Mendel’s law (Wang et al., 2001). It was also found that hGH
transgene could be transmitted to F4 generation and initiate
its transcription normally (Sun et al., 2000). Besides, the
flanking sequences of the integration sites in the F4 genome
417G. Wu et al. / Aquat. Living Resour. 16 (2003) 416–420
were characterized and the relationship between integration
sites and transgenic performance was analyzed (Zeng and
Zhu, 2001). Recently, the experiment of gene targeting based
on the strategy of dual-fluorescence positive–negative selec-
tion was successfully performed in cultured cells and living
embryos (Wang, 2000). The techniques of cell culture and
nuclear transplantation, fortunately, have been developed
and become familiar in fish (Zhu and Sun, 2000). It will be
another promising way to generate stable line of transgenic
fish by nuclear transplantation with in vitro genetically modi-
fied cells. This will considerably overcome the integration
mosaicism in fish transgenesis.
Why did GH-transgenic fish gain higher special growth
rate (SGR) than the controls? According to the study on
growth and energy budget, GH-transgenic common carp
channeled less energy to metabolism and more to protein
synthesis than the controls. Compared with the controls, F2
GH-transgenic common carp showed higher wet body
weight, dry body weight and feed conversion efficiency. In
total, F2 GH-transgenic fish utilize 6.62% more energy for
synthesization than the controls. This phenomenon is called
“fast-growing and less-eating” effect (Cui et al., 1996). On
the other hand, growth and feed utilization by F4 GH-
transgenic common carp fed diets with different protein
levels (20%, 30%, and 40%) were studied. No matter what
protein level was fed with, the transgenics showed higher diet
conversion efficiency and higher growth rate than the con-
trols. When fed with low protein level diet, the higher growth
rate of transgenic common carp mainly depended on taking
more food. When dietary protein was adequate, however,
higher energy conversion efficiency drove transgenic com-
mon carp superior in growth performance. That is to say,
GH-transgenic fish could not only gain growth improvement
but also have a “feed-saving” effect (Fu et al., 1998). Under
the same breeding condition, the transgenics had higher
contents of dry matter, sarcous protein and amino acids while
fewer lipids than the controls. Further analysis revealed there
was no significant difference in amino acids composition
between the transgenics and the controls (Fu et al., 2000).
It should be concluded that, introduced GH gene not only
could be integrated into the host genome and inherited to the
offspring, but also could express normally, which resulted in
the transgenic fish with many valuable traits, such as “fast-
growing and less-eating” and “high-protein and low-lipid
contents”. The model study of GH-transgenic common carp
has laid a foundation for fish transgenic breeding and shown
great potential for aquaculture.
3. “All-fish” GH-transgenic common carp
Under the consideration for bio-safety and bio-ethics,
both MT-1 promoter that needs heavy metal ion inducing and
hGH that codes a kind of human protein are not encouraged
to be used for the purpose of fish breeding. For this reason,
the tentative plan of constructing “all-fish” gene that contains
only piscine sequences has been proposed (Zhu, 1992a). In
the early 1990s, common carp b-actin (CA) and grass carp
(Ctenopharyngodon idellus) growth hormone (gcGH) were
successively cloned (Liu et al., 1990; Zhu et al., 1992).
Subsequently, CA promoter and the coding sequence of
gcGH were linked and subcloned to pUC118 to make the
“all-fish” constructs, pCAgcGH and pCAgcGHc (Zhu,
1992b).
When the “all-fish” constructs were microinjected into the
fertilized eggs of common carp, they showed to be efficient
by dramatically improving the growth rate of the transgenics.
At 4-month, the transgenic common carp reached a weight of
2.75 kg, while the largest control was only 1.4 kg. At 17-
month, one transgenics weighted 7.65 kg, more than double
of the largest control (Wang, 2000). Furthermore, the middle-
scale trial of F1 “all-fish” transgenic common carp has been
carried out with parallel experiments. In average, the F1
transgenics gained growth rate by 42–80% over the controls,
according to the data collected every 20 days for 5 months.
The feeding conversion ratio (total food weight for per unit of
gained body weight) of transgenics was 1.10, whereas that of
control was 1.35 (Zhu, 2000). It could be concluded that
“all-fish” GH-transgenic common carp could gain both
higher growth rate and feed conversion efficiency than the
controls in field farming, just consistent to the findings in
laboratory. It is obvious that those farmers who raise “all-
fish” transgenic fish will gain the yield of fish production,
while the feeding costs will be greatly reduced.
4. Environmental safety of transgenic common carp
Nevertheless, before the application of “all-fish” trans-
genic common carp in aquaculture, the safety issues concern-
ing their potential impact on environment need urgently to be
evaluated. In a broad view of genetics, the crossbreeding is in
fact a kind of transgenesis—a whole genome trans-
genesis—which occurs ever since fishes appeared in natural
water body. Compared with crossbreeding, the transgenic
fish is merely an “artificial variety” of the normal non-
transgenics. In this regard, transgenic fish will likely pose
less impact on the environment than those hybrid fishes that
have been applied to aquaculture for a long history.
In a general opinion, transgenic fish is actually a newborn
to this world, so that we need some carefully conducted
studies to reach a conclusion. According to Cui’s investiga-
tion, the transgene could flow among the same species by
natural reproduction while not among different species (Cui,
1998). To avoid the potential risk, sterile technology could be
utilized in the breeding of transgenic fish. Fortunately, a
fertile strain of tetraploids had been successfully produced by
crucian carp × common carp, and the strictly sterile triploid
could be obtained by crossing diploid common carp against
the tetraploid (Liu et al., 2001). The “all-fish” GH transferred
tetraploids weighed over three times more than the controls
after 240 days rearing (Zeng et al., 2000). By crossing the
transgenic common carp diploids against the tetraploids, a
418 G. Wu et al. / Aquat. Living Resour. 16 (2003) 416–420
sterile strain of “all-fish” transgenic triploids was success-
fully produced (Zhu, 2000). Just like GH-transgenic dip-
loids, GH-transgenic triploids showed significantly im-
proved growth rate and feed conversion efficiency. Under
economic estimation, to raise the fast-growing transgenic
triploids can benefit the fish farmers by 52% over to raise the
normal common carp (Zhu, 2000).
5. Food safety of transgenic common carp
Since the transgenic common carp are expected to be one
kind of food supply for human being, the issue of food safety
should be considered seriously. Due to the wide application
of the transgenic techniques in agriculture, the food safety of
transgenics has become the focus of the public concerns. A
thorough and careful analysis of the food safety of transgenic
fish needs to be conducted and it will be helpful to make the
public understand and accept the laboratory-produced organ-
isms.
At present, the widely accepted principle on food safety
evaluation of foods produced by modern biotechnology is the
“substantial equivalence principle”, which was first proposed
by OECD (European Organization for Economic Coopera-
tion and Development) (OECD, 1993). When compared with
the widely cultured non-transgenic common carp, the “all-
fish” GH-transferred common carp do not produce any new
proteins and other new biological products; and strictly
speaking, they only produce a kind of novel piscine growth
hormone. While grass carp and common carp belong to the
same family and share 97% homology in amino acids se-
quence of the growth hormones (Zhu et al., 1992). Moreover,
the polypeptide of growth hormone is very sensitive to acid,
alkali and heat. It is undoubted that the physiological func-
tion of novel grass carp GH can be easily destroyed during
routine cooking. It is reasonable that the “all-fish” GH-
transgenic common carp is safe enough as daily food and no
further nutrition and toxicology analysis is needed according
to the “substantial equivalence principle”.
Yet the experiment of food safety evaluation of “all-fish”
GH-transgenic common carp was conducted to meet public
concern. Physiological and pathological analysis of the mice
fed with “all-fish” GH-transgenic common carp had been
carried out according to the pathological principles of new
medicines issued by the Ministry of Health of China (Zhang
et al., 2000). Test groups of mice were fed with homogenate
of transgenics at the dosages of 5 and 10 g/kg body weight for
6 weeks, while the control groups were fed with control fish
at the same dosages. In comparison with the control mice, the
test mice did not show any significant difference in growth
performance, general appearance and biochemical analysis
of blood, and histochemical assay of 12 organs, etc.
(P > 0.01). Feeding with transgenic fish did not cause any
impact on the reproduction capacity of the test mice and the
development of the sub-generation of test mice. These results
revealed that “all-fish” GH-transgenic common carp were
substantially equivalent to control common carp in the aspect
of physiology and pathology, and “all-fish” GH-transgenic
common carp were safe enough as a kind of food resources.
6. Conclusion
In view of the transgenic breeding, applications of trans-
genic animals are far behind those in plants. Since the first
transgenic plant, the antiviral tobacco was produced in 1983
(Shaw et al., 1983) following the “super mouse”, the trans-
genic “antiviral tomato” has been authorized by the Food and
Drug Administration (FDA) of the United States for entering
the market 10 years later. By now, there are thousands of
transgenic plants all over the world in filed trial, among
which more than 40 plants have been commercialized (FDA,
2002). However, there is no report on the commercialization
of transgenic animals, since the public and the governments
are more cautious to the application of transgenic animals
than plants.
The laboratory studies and field trials have shown that
“all-fish” GH-transgenic common carp are safe enough to the
environment and human health. More importantly, they
could bring great benefits to both the fish farmers and the
consumers. Therefore, “all-fish” transgenic common carp
could be considered one of the successful examples of the
application of transgenic animals. From scientific point of
view, the mature season of applying “all-fish” transgenic
common carp to aquaculture is coming; while in practice, the
“all-fish” transgenic common carp is waiting for public ac-
ceptance and governmental authorization.
Acknowledgements
This work was supported by the State Key Fundamental
Research of China (Grant No. G2000016109) and the Na-
tional Natural Science Foundation of China (Grant No.
90208024 and 30123004).
References
Anderson, E.D., Mourich, D.V., Fahrenkrug, S.C., LaPatra, S., Shepherd, J.,
Leong, J.A.C., 1996. Genetic immunization of rainbow trout (Oncorhyn-
chus mykiss) against infectious hematopoietic necrosis virus. Mol. Mar.
Biol. Biotechnol. 5, 114–122.
Bending, M.M., 1981. Persistence and expression of histone genes injected
into Xenopus eggs in early development. Nature 292, 65–67.
Cui, Z., 1998. Biosafety assessment of GH-transgenic common carp (Cyp-
rinus carpio L.). Institute of Hydrobiology, ChineseAcademy of Science
Ph.D. thesis.
Cui, Z., Zhu, Z., Cui,Y., Li, G., Xu, K., 1996. Food consumption and energy
budget in MThGH-transgenic F2 red carp (Cyprinus carpio L. red var.).
Chin. Sci. Bull. 41, 591–596.
FAO, 2000. The state of world fisheries and aquaculture 2000. Food and
Agriculture Organization of the United Nations, Fisheries Department,
Rome, Italy.
FDA, 2002. List of Completed Consultations on Bioengineered Foods. U.S.
Food and Drug Administration, Center for Food Safety & Applied
Nutrition, Office of Food Additive Safety, March 2002.
419G. Wu et al. / Aquat. Living Resour. 16 (2003) 416–420
Fu, C., Cui,Y., Hung, S.S.O., Zhu, Z., 1998. Growth and feed utilization by
F4 human growth hormone transgenic carp fed diets with different
protein levels. J. Fish Biol. 53, 115–129.
Fu, C., Cui,Y., Zhu, Z., 2000. Whole-body amino acid pattern of F4 human
growth hormone gene transgenic red carp (Cyprinus carpio) fed with
different protein levels. Aquaculture 189, 287–292.
Hew, C.L., Davies, P.L., Fletcher, G., 1992. Antifreeze protein gene transfer
in Atlantic salmon. Mol. Mar. Biol. Biotechnol. 1, 309–317.
Hew, C.L., Fletcher, G.L., Davies, P.L., 1995. Transgenic salmon: tailoring
the genome for food production. J. Fish Biol. 46 (Suppl. A), 1–19.
Inoue, K., Yamashita, S., Hata, J., Kabeno, S., Asada, S., Nagahisa, E.,
Fujita, T., 1990. Electroporation as a new technique for producing
transgenic fish. Cell Differ. Dev. 29, 123–128.
Khoo, H.W., Ang, L.H., Lim, H.B., 1992. Sperm cells as vectors for intro-
ducing foreign DNA into zebra fish. Aquaculture 107, 1–19.
Li, G., Cui, Z., Zhu, Z., Huang, S., 1996. Introduction of foreign gene carried
by sperms. Acta Hydrobiol. Sin. 20, 242–247.
Lin, S., Gaiano, N., Culp, P., Burns, J.C., Friedmann, T., Yee, J.K., Hop-
kins, N., 1994. Integration and germ-line transmission of a pseudotyped
retroviral vector in zebrafish. Science 265, 666–669.
Liu, Z., Zhu, Z., Roberg, K., Faras, A., Guise, K., Kapuscinski, A.R.,
Hackett, P.B., 1990. Isolation and characterization of b-actin gene of
carp (Cyprinus carpio). DNA Seq. 1, 125–136.
Liu, S., Liu, Y., Zhou, G., Zhang, X., Luo, C., Feng, H., He, X., Zhu, G.,
Yang, H., 2001. The formation of tetraploid stocks of red crucian carp ×
common carp hybrids as an effect of interspecific hybridization. Aquac-
ulture 192, 171–186.
OECD (Organization for Economic Cooperation Development), 1993.
Safety evaluation of foods produced by modern biotechnology: concepts
and principles. OECD, Paris.
Palmiter, R.D., Brinster, R.L., Hammer, R.E., Trumbauer, M.E., Rosen-
feld, M.G., Bimberg, N.C., Evans, R.M., 1982. Dramatic growth of mice
that develop from eggs microinjected with metallothionein-growth hor-
mone fusion gene. Nature 300, 611–615.
Pavlakis, G.N., Hamer, D.H., 1983. Regulation of a metallothionein-growth
hormone hybrid gene in bovine papilloma virus. Proc. Natl. Acad. Sci.
USA 80, 397–401.
Shaw, C.H., Leemans, J., Shaw, C.H., Van Montagu, M., Schell, J., 1983. A
general method for the transfer of cloned genes to plant cells. Gene 23,
315–330.
Sun, Y., Chen, S., Wang, Y., Zhu, Z., 2000. The onset of foreign gene
transcription in nuclear-transferred embryos of fish. Sci. China (Ser. C)
43, 597–605.
Synonds, J.E., Walker, S.P., Sin, F.Y.T., 1994. Electroporation of salmon
sperm with plasmid DNA: evidence of enhanced sperm/DNA associa-
tion. Aquaculture 119, 313–327.
Wang, Y., 2000. Studies on site-specific integration of transgene in trans-
genic fish. Ph.D. thesis, Institute of Hydrobiology, Chinese Academy of
Science.
Wang, R., Zhang, P., Gong, Z., Hew, C.L., 1995. Expression of the antifreeze
protein gene in transgenic goldfish (Carassius auratus) and its implica-
tion in cold adaptation. Mol. Mar. Biol. Biotechnol. 4, 20–26.
Wang, Y., Hu, W., Wu, G., Sun, Y., Chen, S., Zhang, F., Zhu, Z., Feng, J.,
Zhang, X., 2001. Genetic analysis of “all-fish” growth hormone gene
transferred carp (Cyprinus carpio L.) and its F1 generation. Chin. Sci.
Bull. 46, 1174–1177.
Wei, Y., Xie, Y., Xu, K., Li, G., Liu, D., Zhou, J., Li, J., Zhu, Z., 1992.
Heredity of human growth hormone gene in transgenic carp (Cyprinus
carpio L). Chin. J. Biotechnol. 8, 140–144.
Xie, Y., Liu, D., Zou, J., Li, G., Zhu, Z., 1993. Gene transfer via electropo-
ration in fish. Aquaculture 111, 207–213.
Zeng, Z., Zhu, Z., 2001. Transgenes in F4 pMThGH-transgenic common
carp (Cyprinus carpio L.) are highly polymorphic. Chin. Sci. Bull. 46,
143–148.
Zeng, Z., Hu, W., Wang, Y., Zhu, Z., Zhou, G., Liu, S., Zhang, X., Luo, C.,
Liu,Y., 2000. The genetic improvement of tetraploid fish by pCAgcGHc-
transgenics. High Technol. Lett. 7, 6–12.
Zhang, F., Wang, Y., Hu, W., Cui, Z., Zhu, Z., 2000. Physiological and
pathological analysis of the mice fed with “all-fish” gene transferred
yellow river carp. High Technol. Lett. 7, 17–19.
Zhong, J., Wang, Y., Zhu, Z., 2002. Introduction of the human lactoferrin
gene into grass carp (Ctenopharyngodon idellus) to increase resistance
against GCH virus. Aquaculture 214, 93–101.
Zhu, Z., 1992a. Generation of fast growing transgenic fish: methods and
mechanisms. Transgenic fish. World Scientific Publishing Co. Ltd., Sin-
gapore.
Zhu, Z., 1992b. Growth hormone gene and the transgenic fish. In:You, C.B.,
Chen, Z.L. (Eds.), Agricultural Biotechnology. China Science and Tech-
nology Press, Beijing, pp. 106–116.
Zhu, Z., 2000. Collection of the technical materials of the national 863 high-
tech project of China “Middle-scale trial of fast growing transgenic
common carp”. Institute of Hydrobiology, Chinese Academy of Sci-
ences, Wuhan, China.
Zhu, Z., Sun, Y., 2000. Genetic and embryonic manipulation in fish. Cell
Res. 10, 17–27.
Zhu, Z., Li, G., He, L., Chen, S., 1985. Novel gene transfer into the fertilized
eggs of goldfish (Carassius auratus L. 1758). J. Appl. Ichthyol. 1,
31–34.
Zhu, Z., Xu, K., Li, G., Xie, Y., He, L., 1986. Biological effects of human
growth hormone gene microinjected into the fertilized eggs of loach,
Misgurus anguillicaudatus (Cantor). Kexue Tongbao, Acad. Sin. 31,
988–990.
Zhu, Z., Xu, K., Xie,Y., Li, G., He, L., 1989. A model of transgenic fish. Sci.
Sin. (B) (2), 147–155.
Zhu, Z., He, L., Chen, T.T., 1992. Primary-structural and evolutionary
analyses of growth-hormone gene from grass carp (Ctenopharyngodon
idellus). Eur. J. Biochem. 207, 643–648.
420 G. Wu et al. / Aquat. Living Resour. 16 (2003) 416–420
- CitationsCitations29
- ReferencesReferences42
- "Also, Oakes et al. (2007) reported that, the enhancement performance of transgenic Coho salmon was due to enhanced dietary intake. Many authors (Cook et al., 2000; Wu et al., 2003 and Kapuscinski et al., 2007) noted that, growth hormone transgenic fish had feed efficiency better than non-transgenic. Besides, Ron et al. (1995) and Haroun (1999) reported that, tilapia in sea water utilize the feed more efficiently than in fresh water. "
[Show abstract] [Hide abstract] ABSTRACT: This study was conducted to produce a salinity tolerant Nile tilapia,Oreochromis niloticusthroughgenetically modified breeding by introducing a fragmented purified DNA isolated from Artemia,Artemia salinaintothe gonads. Two groupsof adult fish (16 females and 8 males)were chosen to be injected with the foreign DNA intotheir gonads using a hypodermic needle with two different concentrations (10 μg and 5 μg /0.1 ml/fish), besides thecontrol group (4 males and 8 females) carried out. Post-hatching fry which produced from each treatment of DNA werecollected and weighed then transferred separately to glass. Two salinity levels were used to rear the hatching fry duringthe present study-20 ppt (equivalent to half the sea salinity level) and 40 ppt (equivalent to the sea salinity level)-beside the freshwater as a control.The results showed a significant improvement (P≤0.05) in most of the growthperformance parameters of genetically modifiedO. niloticustreated with 10 μg of Artemia DNA compared to thelowest dose of 5 μg of DNA and the control fish reared at 20 ppt of salinity.The results also showed that, the number ofamplified bands detected varied, depending on the primers and DNA treatment. Highly genetic polymorphic percentageranged from (8.00 to 71.79%) with an average of 39.05% using different random primers.The results of the presentwork suggested that, hyper-saline genetically modifiedO. niloticuswith higher growth rate can be produced using afeasible and fastmethodology.- "reduced swimming ability) [91, 92]. The Chinese government has provided funding for the development of studies to assess the environmental safety and food-safety of these fish [89, 90]. Despite these efforts, so far in China no transgenic fish have been commercially produced or approved for consumption [88]. "
[Show abstract] [Hide abstract] ABSTRACT: The RIVM has made an inventory of genetically modified (GM) organisms that could be illegally imported into the European Union, now or in the near future. In recent years, some varieties of genetically modified ornamental fish have appeared illegally on the EU market. The research in the current report focused on genetically modified animals and micro-organisms that have not yet been authorized on the EU market, especially since an inventory of genetically modified crops has already been drawn up. It appears that besides genetically modified ornamental fish, veterinary vaccines and pesticides that contain genetically modified micro-organisms could potentially be illegally imported. Furthermore, ‘medical tourism’ and ‘do-ityourself biology’ may lead to the undesirable introduction of genetically modified organisms into the environment. There are currently no genetically modified food/feed animals, pets, or insects on the market, but this may change in the near future, depending on the admission or rejection of current market applications. This report was commissioned by the Human Environment and Transport Inspectorate, formerly the VROM Inspectorate. One of the report’s objectives is to provide decision-making tools for the Inspectorate with regard to which genetically modified organisms will require the most attention (now and in the near future), how they can be detected and which agency is responsible for the enforcement. The RIVM has examined which genetically modified organisms have already been admitted to the market or could be admitted soon. This was done by consulting the databases of agencies dealing with authorization of genetically modified organisms, both within and outside Europe. In addition, literature and internet resources were studied. Data were also taken from agencies involved in the inspection and enforcement of genetically modified organisms. For each category of organisms within the inventory (ranging from genetically modified bacteria and viruses, insects, fish, and small animals to cattle) an estimation of the likelihood of import was made. Further included is whether an environmental risk assessment is available that may be helpful for assessing the potential risks to human health and the environment.- "Successful production of transgenic fish was first demonstrated in goldfish (Zhu et al. 1985) and 3 years later in zebrafish (Stuart et al. 1988). More than 30 fish species, including many of the major aquaculture species like carp, tilapia, catfish and salmonids, have been genetically engineered with most efforts targeted to enhancing growth and feed conversion efficiency through the transfer of growth hormone (GH) gene constructs (Zhu and Sun 2000; Wu et al. 2003; Devlin et al. 2006). GH transgenesis has shown to result in different effects of growth enhancement in host fish depending on different genetic backgrounds (Devlin et al. 2001Devlin et al. , 2009). "
[Show abstract] [Hide abstract] ABSTRACT: Growth hormone (GH) gene transfer can markedly increase growth in transgenic fish. In the present study we have developed a transcriptional assay to evaluate GH-signal activation (GHSA) in zebrafish embryos. By analyzing the transcription of c-fos and igf1, and the promoter activity of spi2.1, in zebrafish embryos injected with different constructs, we found that overexpression of either GH or growth hormone receptor (GHR) resulted in GHSA, while a synergetic overexpression of GH and GHR gave greater activation. Conversely, overexpression of a C-terminal truncated dominant-negative GHR (ΔC-GHR) efficiently blocked GHSA epistatic to GH overexpression, demonstrating the requirement for a full GHR homodimer in signaling. In view of the importance of signal-competent GHR dimerization by extracellular GH, we introduced into zebrafish embryos a constitutively activated GHR (CA-GHR) construct, which protein products constitutively dimerize the GHR productively by Jun-zippers to activate downstream signaling in vitro. Importantly, overexpression of CA-GHR led to markedly higher level of GHSA than the synergetic overexpression of GH and GHR. CA-GHR transgenic zebrafish were then studied in a growth trial. The transgenic zebrafish showed higher growth rate than the control fish, which was not achievable by GH transgenesis in these zebrafish. Our study demonstrates GH-independent growth by CA-GHR in vivo which bypasses normal IGF-1 feedback control of GH secretion. This provides a novel means of producing growth enhanced transgenic animals based on molecular protein design.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.
This publication is from a journal that may support self archiving.
Learn more