Transgenic Animals

Transgenic Animals

1. BY, SRI RANJANI TALLAM, LECTURER IN ZOOLOGY, D.K(A)GOVT COLLEGE FOR WOMEN, NELLORE. 04/11/2017

2.  A transgenic animal is one that carries a foreign gene that has been deliberately inserted into its genome.  Transgenesis is the process by which mixing up of genes takes place.  Foreign genes are inserted into the germ line of the animal, so it can be transmitted to the progeny.  Transgenic technology has led to the development of fishes, live stock and other animals with altered genetic profiles which are useful to mankind.

3.  First transgenic animal was a ‘ Supermouse ’ created by Ralph Brinster (U Pennsylvania) and Richard Palmiter (University of Washington) in 1982.  It was created by inserting a RAT growth hormone gene in mouse genome.  The offspring was much larger than the parents.  Mouse – common transgenic expt animal.  Other animals include pig, goat, cow, sheep, fish etc.

4. METHODS OF GENE TRANSFER  Retrovirus-mediated gene transfer DNA Microinjection Method  Embryonic stem cell-mediated gene transfer

5. RETROVIRAL MEDIATED GENE TRANSFER

6. DNA Microinjection Method

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8.  Transgenic animals can be created by manipulating embryonic stem cells.  ES cells are obtained from the inner cell mass of a blastocyst.  Transgene is incorporated into the ES cell by Microinjection By a retro virus By electroporation  Transgenic stem cells are grown in vitro.  Then they are inserted into a blastocyst and implanted into a host’s uterus to grow normally.

9. EMBRYONIC STEM CELL METHOD

10.  Medical importance Disease model Bioreactors for pharmaceuticals Xenotransplantation   Agricultural importance Disease resistant animals For improving quality and quantity of milk, meat, eggs and wool production Industrial importance Toxicity sensitive transgenic animals to test chemicals. Spider silk in milk of goat

11. Proteins expressed in Transgenic Animals

12.  Superfish Increased growth and size Growth hormone gene inserted into fertilized egg. Transgenic salmon grows about 10 – 11 times faster than normal fish.  Glo fish GM freshwater zebra fish ( Danio rerio ) Produce by integrating a fluorescent protein gene from jelly fish into embryo of fish.

13.  Alzheimer’s mouse In the brain of Alzheimer’s patients, dead nerve cells are entangled in a protein called amyloid. Mouse made by introducing amyloid precursor gene into fertilized egg of mice . Useful in understanding pathological basis of the disease.  Oncomouse Mouse model to study cancer Made by inserting activated oncogenes.  Knockout mice Loss of function of specific gene(Gene knockout). serve as animal models to study human abnormalities .

14. Growth Differences between Transgenic and Non Transgenic Fish

15.  Enviro pig Pigs have trouble fully digesting a compound known as phytate found in many cereal grains used to feed them. Transgenic pigs are created by introducing phytase gene of E.coli. Phytase enzyme is thus produced in the salvary gland of pig It degrades indigestible phytate with the release of phosphate that is readily digested by pigs.  Pig for organ transplant Pigs with human genes, in order to decrease the chance of organ rejection by human body.

16.  Bioreactors whose cells have been engineered to synthesis marketable proteins.  More economical than producing desired protein in cell culture. 11/2/2017 04/11/2017  Transgenic cattle Transgenic cows are made to produce proteins lactoferrin and interferons in their milk. Prion free cows resistant to mad cow disease.   Transgenic sheep For good quality wool production. CYSTEINE TRANSGENE Transgenic goat Goats that could express tissue plasminogen activator, anti thrombin III, spider silk etc in milk.

17.  Alba, the EGFP (Enhanced Green Flurescent protein) bunny  Created in 2000 as a transgenic artwork .  ANDi was the first transgenic monkey, born in 2000.  “ANDi” stands for “inserted DNA” spelled backwards.  An engineered virus was used to insert the harmless gene for green fluorescence protein (GFP) into ANDi’s rhesus genome.  ANDi proves that transgenic primates can be created, and can express a foreign gene delivered into their genome.

18.  Blurring the lines between species by creating transgenic combinations.  There may be health risks associated with transgenics.  There may be long term effects on the environment when transgenic animals are released into the field.  Various bioethicist argue that it is wrong to create animals that would suffer as a result of genetic alteration.

19.  Transgenic technology is a field that is under constant evolution.  Many transgenic animals have been successfully created for a variety of purposes, and the prospects are enormous.  It holds great potential in many fields including agriculture, medicine and industry.  With proper research and careful use the transgenic animals can go a long way in solving several problems for which science doesn’t have a solution till now.

20. THANK YOU