The flashcards below were created by user
on FreezingBlue Flashcards.
What are reasons to make transgenic animals?
- 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
What methods are used in gene transfer?
- DNA microinjection
- Embryonic stem cell-mediated gene transfer
- Retrovirus-mediated gene transfer
What are the steps in DNA microinjection?
- 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.
What are the potential problems in microinjection?
- 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
What is embryonic stem cell gene transfer?
- 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)
What are the steps in embryonic stem cell gene transfer?
- 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
What are the uses of embryonic stem cells?
- Study human diseases
- Drug discovery
- Study growth and developement
- To inactivate or insert gene
What are the two ways of gene targeting?
- Knock-in - Insert genes into specific site on chromosome
- Knock-out - Remove a gene or part of a gene to inactivate it
How is a retrovirus used to integrate genes into a recipient organism?
- By infecting the organism with virus carrying the gene
- The desired gene can be integrated into the host chromosome
What make an animal transgenic?
- Animals have genes from other species
- Genes either knock-in or knock-out
What are the uses of transgenic animals?
- They are modified to resist diseases and environmental stress
- They are used to manufacture proteins, clotting factors, hormones, growth factors
What is Xenotransplantation?
The use of animal organs in human patients
What is the animal of choice for Xenotransplantation and why?
- They are easy to raise and breed
- Have similar sized organs
- Can be genetically engineered and cloned
What are the concerns about xenotransplants?
- Ethical concerns
- Loss of litter mates
- Fear of diseases
- Required method to screen PERV free organ and organ is not rejected
What are some animal health concerns
- Foot and mouth disease
- Mad cow disease
What is artificial insemination?
- Allows genetically desirable animals to be bred more efficiently and frequently
- Increase genetic diversity of endangered animals
What is conservation biology?
It is used to preserve and protect endangered species of animals
What techniques are used in conservation biology?
- Invitro fertilization for controlled breeding
- Cryopreservation of gametes
- Embryo transfer-preserving fertilized eggs
What are the causes for concern for animal clones?
Animals have many problems- Early death, low cloning success, oversized animals, physical deformities, medical problems