Transgenic animals
What are the transgenic animals?
Purpose
The production of transgenic livestock has the opportunity to significantly improve human health, enhance nutrition, protect the environment, increase animal welfare, and decrease livestock disease.
The aim is that the resulting transgenic organism will express the gene and exhibit some new property or characteristic.
A transgenic animal is one whose genome has been altered by the transfer of a gene or genes from another species or breed.
Advantages
Disadvantages
Increased growth rate
Improved disease resistance.
Improved food conversion rate.
Increased muscle mass.
Improved nutritional value.
Inserted gene has multiple functions.
Breeding problems.
Sometimes leads to mutagenesis and functional disorder.
Low survival rate of transgenic animals.
Dolly was a female domestic sheep,
and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer. Born5 July 1996
She was cloned by Sir lan Wilmut, Keith
"Herman" (Bull)
The transgenic mammal "Herman" the bull was
the genetically modified or transgenic mammal
Example and history
Methods to create transgenic animals
DNA microinjection
Retrovirus-mediated gene transfer
Embryonic stem cell-mediated gene transfer
Transfer of a desired gene construct from another member of the same species or from a different
species into the pronucleus of a reproductive cell. The manipulated cell, which first must be cultured in vitro (in a lab, not in a live animal) to develop to a specific embryonic phase, is then transferred to the recipient female.
-Retroviruses used as vectors to transfer genetic material into the host cell, resulting in a
chimera, an organism consisting of tissues or parts of diverse genetic constitution
Chimeras are inbred for as many as 20 generations until homozygous (carrying the desired transgene in every cell) transgenic offspring are born
Example
The mouse was the first animal to undergo successful gene transfer using DNA microinjection.
Example
The method was successfully used in 1974 when a simian virus was inserted into mice embryos,
resulting in mice carrying this DNA..
Isolation of totipotent stem cells (stem cells that can develop into any type of specialized cell) from embryos
The desired gene is inserted into these cells Cells containing the desired DNA are incorporated into the host's embryo, resulting in a chimeric animal
Example
ES gene transfer involved the curing of many diseases like Parkinson disease,spinal cord injuries,and Alzheimer's diseases.
"supermouse"
First transgenic animal was a "Supermouse" created by Ralph Brinster and 'Richard Palmiter' In 1982.
It was created by inserting a human growth hormone gene in mouse genome.
The offspring was much larger than the parents.
Genetically modified organisms that carry foreign gene in them.
Application
Importance
To obtain information on gene function and regulation as well as on human diseases
Medical importance
Agricultural importance
Industrial importance
Toxicity sensitive transgenic animals to test chemicals.
Spider silk in milk of goat.
Disease model.
Xenotransplantation.
Disease resistant animals.
For improving quality & quantity of milk, meat, eggs & wool production.
To obtain high value products (recombinant pharmaceutical proteins and xeno-organs for humans) to be used for human therapy.
To improve animal products for human consumption
Transgenesis is the process by which mixing up of genes takes place.
Transgenic animal
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