6.3.7: Issues relating to genetic manipulation

Question 1

Modified organism:
Microorganisms, e.g. E.coli
What are the potential benefits?

Answer 1

GM organisms can make…

• Human insulin to treat all diabetics (this was not possible with pig insulin).
• and human growth hormone to treat children with pituitary dwarfism.

Question 2

Modified organism:
Microorganisms, e.g. E.coli
What are the potential hazards?

Answer 2

• Microorganisms could escape into the wild and transfer marker genes for antibiotic resistance to other bacteria.
• However, the GM bacteria are also modified so that they cannot synthesise an essential nutrient and therefore they cannot live outside the lab.

Question 3

Modified organism:
Plants, Bt tobacco and Bt maize
What are the potential benefits?

Answer 3

• In 1985, tobacco plants were genetically modified to produce the toxin normally produced by a bacterium, Bacillus thuringiensis.
• This toxin, Bt, had been used by organic farmers as a pesticide, as it is toxic to insects.
• Because the bacterial gene, Bt, was inserted into some crop plants, the GM crops produced the toxin, eliminating the need to spray it around the environment possibly contaminating other organisms.

Question 4

Modified organism:
Plants, Bt tobacco and Bt maize
What are the potential hazards?

Answer 4

• Bt is toxic to butterflies.
• However, these butterflies do not take nectar from tobacco plants or maize plants in the wild; they feed on milkweed.
• Despite many thousands of hectares of land in the USA being planted with Bt crops, the monarch butterfly has continued to thrive.

Question 5

Modified organism:
Soya beans
What are the potential benefits?

Answer 5

-GM soya beans, resistant to a herbicide (Round-Up Ready), were produced so that weeds competing with the soya plants could be killed with the herbicide.

Question 6

Modified organism:
Soya beans
What are the potential hazards?

Answer 6

• Possible risks include the potential for the gene for herbicide resistance to pass into weeds, producing ‘superweeds’.
• This does not appear to have happened to date.

Question 7

Modified organism:
Golden Rice
What are the potential benefits?

Answer 7

• About 500 000 children each year in India go blind, and some of them die, through a lack of beta carotene, the precursor to vitamin A.
• Golden Rice was genetically modified to contain a gene from daffodils so that beta carotene would be present in the rice grains.
• As rice is the staple food in this region, this seemed a great solution to this problem.

Question 8

Modified organism:
Golden Rice
What are the potential hazards?

Answer 8

-Some people were concerned that farmers would have to buy the seed every year, but the company that developed this rice has offered free licences to farmers so they can keep and replant rice seeds.

Question 9

Modified organism:
Plantains
What are the potential benefits?

Answer 9

• A local biotechnology company in Kenya, Africa Harvest, is producing plantains that are nutritionally enhanced to contain more zinc.
• In areas where people eat very little meat, they may be deficient in zinc, an important enzyme cofactor and essential for regulating insulin secretion.

Question 10

Modified organism:
Plantains
What are the potential hazards?

Answer 10

• Some people fear eating food that contains foreign DNA and worry that inserted genes will somehow be expressed in us.
• However, all the food we eat contains genes and we digest the DNA with specific enzymes, nucleases and nucleotides.

Question 11

Modified organism:
Crop plants resistant to pests
What are the potential benefits?

Answer 11

• A local biotechnology company in Kenya, Africa Harvest is producing crops that are resistant to pests so that when farmers sow these seeds, they do not need to use pesticides.
• Not only is this better for the environment, it is good for farmers.
• Every year in Africa, about 2000 people die through exposure to pesticides while applying them.

Question 12

Modified organism:
Crop plants resistant to pests
What are the potential hazards?

Answer 12

• There were concerns that local farmers might not want the GM seed and would not have the choice to buy non-GM seed.
• However, Monsanto also sells non-GM seeds
• but many farmers see the benefits of the GM seeds and do not want to be exposed to pesticides.

Question 13

Modified organism:
Pathogens
What are the potential benefits?

Answer 13

• Viruses, genetically modified to have no virulence, can be used to make vaccines, as they still have the antigens on their surfaces.
• This reduces the chances of a vaccine making the recipient ill.
• Modified viruses can also be used as vectors in gene therapy.

Question 14

Modified organism:
Pathogens
What are the potential hazards?

Answer 14

-There have been some problems with the use of viruses in gene therapy, as the allele may be inserted into the genome in a way that increases the risk of cancer and interferes with gene regulation.

Question 15

Modified organism:
Mice
What are the potential benefits?

Answer 15

• Since 1974, millions of GM mice have been bred for medical research and used to develop therapies for breast and prostate cancer.
• Other types of mice have had certain genes knocked out so that researchers can find out the function of those genes.

Question 16

Modified organism:
Mice
What are the potential hazards?

Answer 16

• Some people object to the use of animals for medical and pharmaceutical testing.
• However, in the UK, strict regulations govern the welfare of animals used in this way and many of us have benefited from medical protocols developed using animals.

Question 17

Modified organism:
Pharmaceutical proteins
What are the potential benefits?

Answer 17

• Genes for human pharmaceutical proteins, such as alpha antitrypsin to treat hereditary emphysema, can be inserted into goats or sheep, and the human protein they express into their milk is harvested.
• Transgenic mammals were used because this protein is too large for a bacterial cell to synthesise.

Question 18

Modified organism:
Pharmaceutical proteins
What are the potential hazards?

Answer 18

• There are concerns for the welfare of the GM sheep and goats.
• However, these animals are valuable and likely to be well looked after.

Question 19

Modified organism:
Silk
What are the potential benefits?

Answer 19

• Silk is one of the strongest materials known.
• Spiders are impossible to farm but genes for spider silk have been inserted into goats.
• These GM goats produce spider silk protein in their milk.
• Silk can be used for cables, structures (stitches after surgery), artificial ligaments and bullet proof vests.

Question 20

Modified organism:
Silk
What are the potential hazards?

Answer 20

• Concerns were raised about the welfare of the GM goats.

- However, these animals are valuable and likely to be well looked after and not be eaten.