Technology and ethics - GM animals

Question 1

How are genes carried into animal DNA? Which animals are hardest to modify?

Answer 1

• vertabrates hardest to modify - especially mammals
• microinjection
  
  • tiny particles of gold covered in DNA
• modified viruses
  
  • carry new genes into animal DNA

Question 2

What is gene manipulation done in animals?

Answer 2

• pharming (discussed later)
• disease resistance
• modify physiology of farm animals

Question 3

What are two examples of GM animals?

Answer 3

• swine-flue resistant pigs
  
  • gnee from wild African pig into early embryo of European pig, giving them immunity
• faster growing salmon
  
  • produce growth hormones all years roudn
  • grow to adult size in half the time
  • efficient food source

Question 4

What is pharming?

Answer 4

• using GE in the production of human medicines

Question 5

What are the two aspects of pharming?

Answer 5

• creating animal models
  
  • addition or removal of genes so that animals develop certain diseases, acting as models for the development of new therapies
  • e.g. mice have genes deleted to increase likelihood of cnacer
• creating human proteins
  
  • animals used instead of bacteria because they cannot produce complex proteins of eukaryotic cells
  • e.g. human gene introduced in genetic material of fertilised cow, along w promotre sequence so the gene is expressed only in the mammary glands, embryo returned, transgenic cow born containing human protein

Question 6

What are the ethical issues?

Answer 6

• should animals be genetically engineered to act as models of human disease
• is it right to put human genes into animals
• is it right to transfer genes without being certain it will cause no harm
• does GM animals reduce them to commodities
• is welfar comprimised in production of GM animals

Question 7

What is somatic cell gene therapy

Answer 7

• invovles replacing the mutant allele with a healthy allele in the affect somatic body cells
• the potential for helping people with a wide range of sieases is enormous
• successful cases begin to be reported
  
  • e.g. leukaemias, haemophilia, immune diseases
    *

Question 8

What are the difficulties with somatic cell gene therapy?

Answer 8

• difficulty in getting healthy alleles in affected cells and starting and maintaining expression
• healthy allele will be passed on every time a cell divides by mitosis but somatic cells have a limited life, replaced from stem cells which will have the faulty gene
• treated individual will past on faulty allele to offspring

Question 9

What is germ line cell gene therapy?

Answer 9

• insert healthy allele into the germ cells - usually the eggs 0 or into an embryo immediately after fertilisation (As part of IVF)
• baby born healthy with normal allele in place and would pass it on to offspring

Question 10

wHY is germ cell line therapy not done on human?

Answer 10

• ethical and medical concerns ‘designer babies’
  
  • desireable or cosmetic traits
• human impact on germ cells in unknonw
• rights vilated, done without consent