Lecture 15

Question 1

Mouse plagues in Australia

Answer 1

• occur approx. ever 3yrs in grain growing Aus regions
• very expensive (1993 plague = $60million)
• Strychnine now banned
• Current (posion) control methods
  o Mouseoff - Zinc Phosphide bait
  o Canola cards

Question 2

Wild Horses in USA

Answer 2

• Unsustainable increase in wild horse population

- $72 million ($42mil “holding” horses)

Question 3

Zona Pellucida structure - ZP1

• role of gp
• effect of deletion

Answer 3

Role of gp: Structural Integrity

Deletion: Loss of structural integrity

Question 4

Zona Pellucida structure - ZP2

• role of gp
• effect of deletion

Answer 4

Role of gp: 2* Sperm Receptor

Deletion: Thin ZP early, absent later = INFERTILE

Question 5

Zona Pellucida structure - ZP3

• role of gp
• effect of deletion

Answer 5

Role: 1* Sperm Receptor
Deletion: No ZP = INFERTILE

Question 6

Fertilisation steps (6)

Answer 6

Attachment–>Binding–>Acrosome Reaction–> Penetration–>Fertilisation–>Release of cortical granules (block to polyspermy)

Question 7

How do we control populations of animals that are small and widely disseminated?

Answer 7

Virally Vectored Immunocontraception

Question 8

What is the concept of virally vectored immunocontraception (VVI)?

Answer 8

1. Identify protein essential for reproduction
2. Isolate DNA response for production of protein
3. Insert DNA into carrier organism (e.g. virus)
4. Infect target pest animal with modified organism
5. Animals immune system produces antibodies to block reproduction

Question 9

Characteristics of the MCMV vector

Answer 9

• Large genome (235kb and 170 ORFs) allowing insertion of foreign genes
• Persistent infection
• Natural pathogen of mice in Aus

= Effector for vaccination against heterologous antigens

Question 10

What are the mechanisms of infertility?

Answer 10

• Antibodies bind to the ovary in infected mice
• ZP3 antibody titre increases over time
• An increased antibody titre is correlated with improved infertility