Application of transgenic animals in livestock production…

submitted by

T.TAMILSELVAN

over the centuries , animals with new combination of genes have been produced using conventional breeding methods by means of careful selection of particular animals.

Transgenic animals

A Transgenic animal is one whose genome has been changed to carry genes from other species.

A large number of transgenic animals have been created in

Mice Cows Pigs Sheep Goats Fish ..

This is not cloning..!!!

Transgenesis is radically new technology .

Since DNA is the universal genetic code for living organisms it can be completely transferred between unrelated animals to produce organism with useful characteristics.

`

Inserting the transgene :

There are several ways of inserting a transgene

Microinjection : 1. Eggs harvested super-ovulated animals fertilized in vitro. 2. Micro tube use to hold the fertilized egg in place and fine needle used to inject tiny amount of solution containing copies of foreign DNA. 3. Eggs are then introduced into surrogate females.

Use of Retroviral vectors:

These viruses can be used to carry gene of interest into embryonic cells.

Since DNA locates at different sites in different cells the offspring are often genetic mosaics and outbreeding is nesscessary.

Embryonic stem cell transfer :

The genes can be injected into the blastocyst stage of a developing embryo and the resulting foetus will be a chimera .

It is used in mice but not been successful in cattle , sheep ,pigs.

Sperm mediated cell transfer :

spermatozoa act as vectors for transfer of the genetic material .

The sperm is then allowed for Fertilization.

some other techniques which are applied nowadays are :

Primordial germ cell technique. gene targeting.

A Transgene :

TRANSPHARMERS :

Transpharmers are engineered to Over -express a particular gene in mammary gland . First done in animal milk and then shifted to milk to produce drug from milk. Larger animals like Sheeps, Goats , Cows are the target.

Animals :

Scientist at the Rosalind institute in Scotland have played a key role in the development of this technique

Tracey * Transgenic It Produces Human alpha -1 prokinase inhibitor in milk. Treatment of Cystic Fibrosis.Polly (1997) : It is the first transgenic lamb produced by nuclear transfer.

Herman : Gen pharm international in California engineered the first transgenic Bull “HERMAN”.

It contains the Human Lactoferrin , the source of iron for human beings . Cows milk does not contain it.

SUPER PIG : Pig that grow bigger and faster , thus producing more

efficient food source. These pig expressed the Human growth hormone . It has many health problems.

Applications: In livestock , the Transgenic technology is used to produce

animals with resistant to diseases.

Sheep could be made resistant to “Fly-strike” by producing Chittinase in their skin to kill larvae.

Transgenic pigs with phytase expressed in their saliva efficiently digest dietary phytate , decreasing the phosphate in excretion.

Wool growth in sheep's is enhanced.

Sows over expressing Bovine alpha – lacta-albumin in their milk helps in increased piglet growth and health.

Increased feed utilization efficiency from dietary roughage in Ruminants.

Size of live stock is improved.

Transgenic cows exist that produce more milk or milk with less lactose or cholesterol , and rich protein content.

Pigs and cattles that have more meat on them.

Eggs can be made healthier with high quality protein.

Animals with disease –resistance are produced.

The first transgenic cow “ ROSIE” produce human protein enriched milk.

Benefits : Specificity speed flexibility Economical

Risks : Animal health Virus transfer. Dissemination.

This Transgenic technology is still experimental.

THANK YOU .!.!.!