Transgenic Animals: Methodology and Applications •Transgenic mice: methodology (Retrovirus vector, DNA microinjection, Engineered embryonic stem cell, Cre-loxP recombination system, High capacity vectors) •Transgenic mice: applications (Alzheimer disease, test systems, conditional regulation, control of cell death) •Cloning livestock by nuclear transfer •Transgenic cattle, sheep, goats and pigs •Transgenic birds •Transgenic fish
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Transgenic Animals: Methodology and Applicationsstaff.unila.ac.id/gnugroho/files/2020/04/Transgenic-Animals.pdf · Transgenic Animals: Methodology and Applications •Transgenic mice:
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Genetically engineered embryonicstem (ES) cells can be used to createtransgenic animals, but this method islabor intensive and used to allow forgene targeting via homologousrecombination.
Transgenic mice can be produced with highcapacity vectors
• Generally done by microinjection of numerous genescontained in a YAC
• Production of mice that can produce humanantibodies is one notable example
• Generally done by microinjection of numerous genescontained in a YAC
• Production of mice that can produce humanantibodies is one notable example
Transgenic mice/animal: applications
• Transgenic models for Alzheimer disease, amyotrophic lateralsclerosis, Huntington disease, arthritis, muscular dystrophy,tumorigenesis, hypertension, neurodegenerative disorders,endocrinological dysfunction, coronary disease, etc.
• Using transgenic mice as test systems (e.g., protein [CFTR] secretioninto milk, protection against mastitis caused by Staphylococcusaureus using a modified lysostaphin gene)
• Conditional regulation of gene expression (tetracycline-induciblesystem in Fig. 21.19)
• Conditional control of cell death (used to model and study organfailure; involves the organ-specific engineering of a toxin receptorinto the mice and then addition of the toxin to kill that organ)
• Transgenic models for Alzheimer disease, amyotrophic lateralsclerosis, Huntington disease, arthritis, muscular dystrophy,tumorigenesis, hypertension, neurodegenerative disorders,endocrinological dysfunction, coronary disease, etc.
• Using transgenic mice as test systems (e.g., protein [CFTR] secretioninto milk, protection against mastitis caused by Staphylococcusaureus using a modified lysostaphin gene)
• Conditional regulation of gene expression (tetracycline-induciblesystem in Fig. 21.19)
• Conditional control of cell death (used to model and study organfailure; involves the organ-specific engineering of a toxin receptorinto the mice and then addition of the toxin to kill that organ)
Another Transgenic mouse application:Marathon Mice
Instead of improving times by fractions of a second, thegenetically enhanced “marathon” mice (above, on thetreadmill in San Diego) ran twice as far and nearly twiceas long as ordinary rodents. The peroxisomeproliferator-activated receptor (PPAR-delta) gene wasoverexpressed in these transgenic mice. For details, seehttp://www.salk.edu/otm/Articles/PLoSBiology_October2004.pdf
Dr. Ron Evans and one of his genetically engineered“marathon” mice. The enhanced PPAR-delta activitynot only increased fat burning, but transformedskeletal muscle fibers, boosting so-called "slow-twitch" muscle fibers, which are fatigue resistant,and reducing 'fast-twitch' fibers, which generaterapid, powerful contractions but fatigue easily.
And then there is “transgenic art” with GFP…
Fig. 21.22 Cloninglivestock by nucleartransfer (e.g., sheep)
“Hello Dolly”
And now there is pet cloning for a “small” fee…
Nine-week-old "Little Nicky" peers out fromher carrying case in Texas. Little Nicky,a cloned cat, was sold to its new ownerby Genetic Savings and Clone for $50,000in December 2004.
August 07, 2008 | Bernann McKinney with one ofthe 5 puppies cloned from Booger, her late petpit bull. It cost her $50,000. When Booger wasdiagnosed with cancer, a grief-stricken McKinneysought to have him cloned -- first by the now-defunct Genetic Savings and Clone, and then bySouth Korean company RNL Bio.
Transgenic cattle, sheep,goats, and pigs
• Using the mammary gland as abioreactor (see adjacent figure)
• Increase casein content in milk
• Express lactase in milk (to removelactose)
• Resistance to bacterial, viral, andparasitic diseases
• Reduce phosphorous excretion
• Using the mammary gland as abioreactor (see adjacent figure)
• Increase casein content in milk
• Express lactase in milk (to removelactose)
• Resistance to bacterial, viral, andparasitic diseases
• Reduce phosphorous excretion
Table 21.2 Some human proteins expressed inthe mammary glands of transgenic animals
• Erythropoietin• Factor IX• Factor VIII• Fibrinogen• Growth hormone• Hemoglobin• Insulin• Monoclonal antibodies• Tissue plasminogen activator (TPA)• α1-antitrypsin• Antithrombin III (the first transgenic animal drug, an
anticlotting protein, approved by the FDA in 2009)
• Erythropoietin• Factor IX• Factor VIII• Fibrinogen• Growth hormone• Hemoglobin• Insulin• Monoclonal antibodies• Tissue plasminogen activator (TPA)• α1-antitrypsin• Antithrombin III (the first transgenic animal drug, an
anticlotting protein, approved by the FDA in 2009)
“Enviropigs”
• Transgenic pigs expressing thephytase gene in their salivary glands
• The phytase gene was introduced viaDNA microinjection and used theparotid secretory protein promoterto specifically drive expression in thesalivary glands
• Phytate is the predominant storageform of phosphorus in plant-basedanimal feeds (e.g., soybean meal)
• Pigs and poultry cannot digestphytate and consequently excretelarge amounts of phosphorus
• “Enviro-pigs” excrete 75% lessphosphorus
• Microinjected an E. coli phytasegene under the control of a mouseparotid secretory protein promoter
• Transgenic pigs expressing thephytase gene in their salivary glands
• The phytase gene was introduced viaDNA microinjection and used theparotid secretory protein promoterto specifically drive expression in thesalivary glands
• Phytate is the predominant storageform of phosphorus in plant-basedanimal feeds (e.g., soybean meal)
• Pigs and poultry cannot digestphytate and consequently excretelarge amounts of phosphorus
• “Enviro-pigs” excrete 75% lessphosphorus
• Microinjected an E. coli phytasegene under the control of a mouseparotid secretory protein promoter
EnviropigTM an environmentally friendlybreed of pigs that utilizes plantphosphorus efficiently.
Fig. 21.32 Establishingtransgenic chickens bytransfection of isolated
blastoderm cells• Resistance to viral, bacterial,
and coccidial diseases
• Better feed efficiency
• Lower fat and cholesterollevels in eggs
• Better meat quality
• Eggs with pharmaceuticalproteins in them
• Resistance to viral, bacterial,and coccidial diseases
• Better feed efficiency
• Lower fat and cholesterollevels in eggs
• Better meat quality
• Eggs with pharmaceuticalproteins in them
Transgenic fish• Genes are introduced into fertilized eggs by DNA microinjection or
electroporation• No need to implant the embryo; development is external• Genetically engineered for more rapid growth using the growth hormone
gene (salmon, trout, catfish, tuna, etc.)• Genetically engineered for greater disease resistance• Genetically engineered to serve as a biosensor for water pollution• Genetically engineered for a novel pet (Glofish-see http://glofish.com/)
• Genes are introduced into fertilized eggs by DNA microinjection orelectroporation
• No need to implant the embryo; development is external• Genetically engineered for more rapid growth using the growth hormone
gene (salmon, trout, catfish, tuna, etc.)• Genetically engineered for greater disease resistance• Genetically engineered to serve as a biosensor for water pollution• Genetically engineered for a novel pet (Glofish-see http://glofish.com/)
Transgenic fish (more detail)• Salmon were genetically engineered for more rapid growth using the growth
hormone gene under the control of the ocean pout antifreeze protein genepromoter and 3’ untranslated region (currently under FDA consideration)
• Madaka fish were genetically engineered to serve as biosensors forenvironmental pollutants (e.g., estrogens) by using an estrogen-induciblepromoter (the vitellogenin promoter) to control expression of the GFP gene