Lecture 3 - Biotechnology in Animal Gene Knockout and Cloning.

Question 1

What is MOET and ONBS?

Answer 1

MOET = is the process of superovulating, fertilising, recovering embryo’s and embryo transferring
ONBS - Open nucleus breeding scheme

Question 2

What are indicator traits?

Answer 2

Genetically correlated traits such as testicular size with fertility, FSH in ewe lambs.

Question 3

What is the gene knock out?

Answer 3

Technology which allows for specific loss of a gene in mice which unlike transgene it is targetted to s specific site on the DNA.

Question 4

What is ES, ICM and pluripotent?

Answer 4

ES - embryonic stem cells
ICM - inner cell mass od blastocyst, this becomes the foetus.
Pluripotent - are cells that can become any cells

Question 5

Steps of knock out process?

Answer 5

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.

Question 6

Example of knockout genes?

Answer 6

GDF8 which is a knock out gene where there is twice the muscle mass of wild type animals.

Question 7

How is cloning different to the transgenic process?

Answer 7

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.

Question 8

Problems with cloning?

Answer 8

• 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).

Question 9

What are some advantages of cloning?

Answer 9

• 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

Question 10

What is AI ?

Answer 10

Artificial insemination. this is the most globally adopted animal technology

Question 11

What are advantages of AI?

Answer 11

• high intensity and accuracy sire selection
• reduces disease transmission
• accurate records of pedigrees
• reduces lethal genes

Question 12

What are disadvantages of AI?

Answer 12

• insemination needs to coincide with ovulation
• requires training
• long distance affects viability of semen

Question 13

What is ET?

Answer 13

Embryo transfer where hormones are used to superovulate (PMSG or FSH). Transfer of embryos to recipient dams.

Question 14

What are the advantages of ET?

Answer 14

• 25 calves from 1 cow
• ET is cheaper than using live animals
• reduced import of disease
• genetically similar progeny

Question 15

Disadvantages of ET?

Answer 15

• expensive
• surgical procedure can be risky to dams
• needs techniques
• success rate varies with skills

Question 16

What is sex separation?

Answer 16

a high speed cytometric separation of X and Y bearing chromosomes. This allows for the desired sex of animals to be produced

Question 17

What are hormonal essays used for?

Answer 17

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.

Question 18

How is biotechnology used to improve animal nutrition?

Answer 18

• increases digestibility of low quality forages by the use of enzymes (lignase), chemical treatment and microbial breakdown.

Question 19

How is bioctechnology used to improve animal health?

Answer 19

DNA is used to make vaccine to deal with vaccines.

ELISA reveals currents infections