5.20 - Cloned transgenic animals

- animals that are cloned are genetically identical 
- transgenic refers to an organism with DNA from 2 or more organisms 


- commercial production of antibodies 


-cow - obtain egg cell 
- human - take a cell - using restriction enzymes, going to take the 'gene antibody production' 


1. in the egg cell - first step is to knock out the cow antibody production gene 
2. Add human gene - transfer from human cell
3. Cows cell is then developed by mitosis to form a clone of cells - embryo - transferred to the surrogate mother 
4. These then produce genetically identical calves 


In this example, the gene for antibodies is expressed and the antibodies are then collected in the milk - this is the human antibody not cow - large commercial scale

5.19 - Mammal Cloning

sheep 1 = Original --genetically identical to clone--> dolly 


- need to obtain genetic info from 1. - done by removing a diploid cell (has a full set of genetic information) 
- at the same time - need to obtain a cell that has a tendency to divide 
sheep 2. completely different animal - has been treated with hormones to produce eggs 
- egg cell - tends to divide 
- do not want the genetic information of the egg and so it is removed (enucleated) 


- take the cell with the genetic information (want to copy) and the cell from the egg which wants to divide and FUSE them together 
- when fusing them together we have the genetic information and a cell that wants to divide 
- the combination of the two results in many cell divisions (like mitosis) to form a ball of cells (blastula - embryonic sheep - genetically identical to sheep 1) 


-embryo (blastula) of sheep 1 is placed into another sheep 3 - which is the surrogate mother 
- the embryo will grow into a fetus 
- this fetus is the clone of sheep 1 and is what we call dolly - it is genetically identical to sheep 1 
- this means they are a clone, even though their age is very different 

5.18 - Commercial plant growing

- Plant has characteristics which are considered commercial so therefore desirable and so want to make copies of this plant 


- sexual reproduction causes loss of qualities that make it valuable as a commercial plant 


- use a cloning technique to get many plants of the same quality
- commercially, that keeps the product the same so that they can be sold
- technique used is micropropagation 

5.17 - Micropropagation

Looking for characteristics of a plant that are desirable - want to produce more plants of the same kind 


if sexual reproduction - the offsprings will differ and so we have to use micropropagation


Process: 
- Take tissue from the shoot tip or the roots 
- Aseptic conditions (free from contamination) 
- Cut the tissue into many small parts 
- Transfer tissue to petri dish - contains nutrient agar - variety of minerals, rooting compounds and other plant hormones - to encourage growth into small clones of original plants 


- In this process you make many clones of the original plant - all genetically identical to the original plant 

5.16 - Transgenic Organism

- video 5.13: Bacterial cell became transgenic because it had the bacterial DNA and Human DNA (plasmids held Insulin gene)

- this is a transgenic organism 

- video 5.15: Maize DNA and transferred into it was the BT gene 

- this is a transgenic organism 

5.11 - Breeding Animals

- Animal: cow 

- desired characteristic: milk yield 

- the farmer would collect all the milk but take the cows that produce 150ml to be the breeding cows in the next generation

- the farmer then selects the cows with high yield to become the breeding cow in the next breeding population 

- as we progressively select, we are able to change the desired characteristic to develop it - by selective breeding 

- for this to work, milk yield must be genetic (under the control of genes) 

5.10 - Breeding plants

- The number of rice grains is under the control of the genes 

- The farmer wants to increase the number of rice grains per plant to then increase the yield

- The farmer notices that some plants have 6 grains per stem, others have 8 grains per stem and others have 10 grains per stem 

- The farmers decision is to harvest the grains with 6 or 8 but use the 10 grains for planting 

- In the next generation of rice he notices that the grains are increased to 8 grains per stem, 10 grains per stem and 12 grains per stem and so he harvest the 8 and 10 grains and selects the 12 grains for planting and breeding 

- In this way, the number of grains of rice found on the plant will gradually increase which will increase the yield 

- This is an example of selective breeding