Introduction to Biotechnology

• To make a model animal to study animal diseases
• Introduce economical important traits in farm animals
• For production of antibody and growth hormones
• Help transfer genes across species

• DNA microinjection
• Embryonic stem cell-mediated gene transfer
• Retrovirus-mediated gene transfer

• Identify the gene of interest
• Clone the gene in the proper vector
• Microinject the cloned gene directly into the pronucleus of a single fertilized egg before first cell division occurs
• Implant the egg into surrogate mother
• Allow embryo to develop to birth
• Demonstrate that the foreign gene has been incorporated into the host genome and it is heritable in at least one offspring.

• Few injected eggs survive
• The gene inserts itself into chromosome at random
• Not all of the cells in the animal receive the gene
• The gene is not expressed in large enough amounts

• Producing differentiated cells from undifferentiated cells, by maintaining the potential of undifferentiated stem cells
• Used for targeted gene replacement (put the gene on the right chromosome)

• ES cells removed from embryo
• Transfection- Gene of interest is inserted in the the embryo
• The gene is targeted by homologous recombination and selective markers
• The ES cells with the correct gene are inserted into blastocysts (partially developed embryos) which are implanted into the mother animal
• Offspring are screened for trait of interest

• Study human diseases
• Drug discovery
• Study growth and developement
• To inactivate or insert gene

• Knock-in - Insert genes into specific site on chromosome
• Knock-out - Remove a gene or part of a gene to inactivate it

• By infecting the organism with virus carrying the gene
• The desired gene can be integrated into the host chromosome

• Animals have genes from other species
• Genes either knock-in or knock-out

• They are modified to resist diseases and environmental stress
• They are used to manufacture proteins, clotting factors, hormones, growth factors

The use of animal organs in human patients

• Pigs
• They are easy to raise and breed
• Have similar sized organs
• Can be genetically engineered and cloned

• Ethical concerns
• Loss of litter mates
• Fear of diseases
• Required method to screen PERV free organ and organ is not rejected

• Foot and mouth disease
• Mad cow disease
• Coccidiosis
• Trypanosmoiasis
• Theileriosis

• Allows genetically desirable animals to be bred more efficiently and frequently
• Increase genetic diversity of endangered animals

It is used to preserve and protect endangered species of animals

• Invitro fertilization for controlled breeding
• Cryopreservation of gametes
• Embryo transfer-preserving fertilized eggs

Animals have many problems- Early death, low cloning success, oversized animals, physical deformities, medical problems