Flashcards in Lecture 3 - Biotechnology in Animal Gene Knockout and Cloning. Deck (19):
What is MOET and ONBS?
MOET = is the process of superovulating, fertilising, recovering embryo's and embryo transferring
ONBS - Open nucleus breeding scheme
What are indicator traits?
Genetically correlated traits such as testicular size with fertility, FSH in ewe lambs.
What is the gene knock out?
Technology which allows for specific loss of a gene in mice which unlike transgene it is targetted to s specific site on the DNA.
What is ES, ICM and pluripotent?
ES - embryonic stem cells
ICM - inner cell mass od blastocyst, this becomes the foetus.
Pluripotent - are cells that can become any cells
Steps of knock out process?
ES cells are grown on tissue culture where the altered gene is introduced and copies of desired genes are grown.
ES cells were injected into early embryo and introduced into forster mother.
Example of knockout genes?
GDF8 which is a knock out gene where there is twice the muscle mass of wild type animals.
How is cloning different to the transgenic process?
In cloning they remove the nucleus and electricity is used to fuse the egg and nucleus which is then placed in a donor.
Transgenic genes are placed in the nucleus.
Problems with cloning?
- the success rate is low 1-3% in comparison to IV fertilisation which has a 20-50% success rate.
- sudden death syndrome where they die of heath issues.
- genetic anomalies
- placental defects and cardiac defects
- many suffer from LOS (large offspring syndrome).
What are some advantages of cloning?
- more uniform expression of transgenic genes
- allows for rapid expansion to large flocks or herds of transgenic animals.
- conservation cloning which is the cloning of extinct or endangered animals
What is AI ?
Artificial insemination. this is the most globally adopted animal technology
What are advantages of AI?
- high intensity and accuracy sire selection
- reduces disease transmission
- accurate records of pedigrees
- reduces lethal genes
What are disadvantages of AI?
- insemination needs to coincide with ovulation
- requires training
- long distance affects viability of semen
What is ET?
Embryo transfer where hormones are used to superovulate (PMSG or FSH). Transfer of embryos to recipient dams.
What are the advantages of ET?
- 25 calves from 1 cow
- ET is cheaper than using live animals
- reduced import of disease
- genetically similar progeny
Disadvantages of ET?
- surgical procedure can be risky to dams
- needs techniques
- success rate varies with skills
What is sex separation?
a high speed cytometric separation of X and Y bearing chromosomes. This allows for the desired sex of animals to be produced
What are hormonal essays used for?
These are hormones which are used to monitor reproductive function and superovulation e.g. melatonin, progesterone and PMSG.
this is expensive and requires improved management and nutrtion for litter survival.
How is biotechnology used to improve animal nutrition?
- increases digestibility of low quality forages by the use of enzymes (lignase), chemical treatment and microbial breakdown.