L8- Transgenic Animals Flashcards
Why genetic engineering/ advantages of animal biotechnology?
- INCREASE GLOBAL DEMAND FOR FOOD
- World population more than doubled since 1950 - INCREASE SUSTAINABILITY
- Size of productive land is finite - ACCELERATION OF GENETIC PROGRESS
- Overcome limitations of conventional breeding techniques
- Inter-species gene transfers - REDUCE DEPENDENCE ON CHEMOTHERAPY
- Engineered resistance to pathogens and parasites
- New molecular vaccines - DETECTION OF DISEASE
- Early detection of disease and gene abnormalities - GENETIC PRESERVATION
- Accurate characterisation of gene pool
- Rescue of endangered species
- Enhance preservation of diversity
Disadvantages of animal biotechnology
PUBLIC PERCEPTION
- Fear of GMOs
- Fear of the unknown
ANTIBIOTICS INTO OUR FOOD SYSTEM
- antibiotic-resistant bacteria
Examples of problems with transgenic animals:
(problems not directly related with the genes inserted/ modified but with physiology of the animal)
- Mastitis in transgenic cows that produce high amounts of milk
- Transgenic fish less ability to swim, reduce viability (inability to get sexual maturity)
- Transgenic sheep require more care
- Transgenic pigs have increased arthritis, bone thickening, infertility
How animal biotechnology may be used to improve meat production?
GROWTH HORMONE (GH):
- stimulates bone and muscle growth
- it is a type of mitogen (encourages cell division) which is speific only in certain kinds of cells
- GH is a stress hormone that raises the concentration of glucose and free fatty acids -> builds up tissue of the body (anabolic)
INSULIN-LIKE GROWTH FACTOR (IGF-1):
- stimulates cell proliferation (synthesis of DNA and protein)
- similar in molecular structure to insulin
- has an important role in childhood growth ans anabolic effects in adults
Examples of how animal biotechnology may be used to improve meat production?
GROWTH STUDIES IN PIGS:
- hGH and pGH experimented with
- Increase growth rate and feed efficiency
> Transgenic pigs: more lean meat, less fatty meat
> Side effects: increased arthritis, bone thickening, infertility…
GROWTH MANIPULATION IN FISH:
- Insertion of additional GH genes
> Dramatic growth rate almost 3-11 times faster eg. Transgenic Atlantic salmon
> Problem with transgenic fish: ecological effectss of escape into the wild, reduced swimming ability, reduced viability of transgenic trout
How animal biotechnology may be used to improve milk production?
IMPROVED YIELD AND COMPOSITION OF MILK
- Increased yield beyond the natural genetic potential
- > bovine somatotrophin genes
- Produce milk with modified nutrient content
- > lactose, fat and protein
- Value added milk containing beneficial attributes- “nutraceuticals”
- > eg. enriched with omega-3 fatty acids
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
- Cold-water tolerance in fish
- Wool production
- Disease resistance
- Reproduction and fertility
- Improved selection
- Pollution monitoring
- Animal nutrition
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
COLD-WATER TOLERANCE IN FISH
TRANSGENIC
- Cold-water tolerance gene= “antifreeze gene”
- Genes were isolated from cold water fish (eg. ocean pout) and inserted into Atlantic salmon
- Used to expand ecological range
ISSUE:
- Should we introduce fish to previously inhospital environments?
- Native wildlife may be displaced
- Damaging the ecosystem
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
WOOL PRODUCTION
WOOL PRODUCTION
- Cysteine is the 1st limiting amino acid in wool growth
- Inserted CysE and CysK genes isolated from E-coli into mice then into sheep
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
DISEASE RESISTANCE
DISEASE RESISTANCE
- “knock out” genes predisposing animals to disease
- Inserting resistance genes
eg. Chitinase gene into cattle to induce insect pest resistance- tseste flies
Chitinase is a plant enzyme that degrades chitin (component of te digestive tract of insects)
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
REPRODUCTION & FERTILITY
REPRODUCTION & FERTILITY
- Target fertility genes e.g. Fec B
Manipulation of fertility targets:
- regulation of the expression of gonadotrophin receptors e.g. oestrogen receptor genes in pigs
- growth factor binding protein genes in follicles
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
IMPROVED SELECTION
IMPROVED SELECTION
- Identification of genetically superior animals
- > accurate genetic marker assisted selection: identify poor performers early
- Verification of authenticity
- > Checking pedigree
- > Quality control- checking imports, distinguishing meat/ milk products from different animals
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
POLLUTION MONITORING
POLLUTION MONITORING
- Transgenic
- > genetically engineering golden zebra fish which glow on exposure to traces of PCBs
- > Water quality
How animal biotechnology may be used to improve aspects of agriculture not associated with meat and milk production?
ANIMAL NUTRITION
ANIMAL NUTRITION
- Target rumen micro-organism
- Insertion of genes for more potent cellulases
- > To increase the rate & extent of rumen fibre digestion: enhances utilization of poor quality forages (straws)
- > Less methane: use energy to produce milk instead
- > More sustainable
- Insertion of genes for new enzymes
E.g. Enviropig
