Final Exam - Note Pack 6

Question 1

Tortipotent

Answer 1

An entire plant can be generated from one cell. Most cells are tortipotent.

Question 2

Transgenic Animal

Answer 2

One whose genetic composition has been altered by the addition of exogenous DNA

Question 3

Transgene

Answer 3

DNA introduced into a transgenic animal

Question 4

Germ Lines

Answer 4

Cells that produce gametes (sperm or egg). Changes in cells can be passed to offspring.

Question 5

Somatic Cells

Answer 5

Cells that make up the majority of the body (non-germ line cells)

Question 6

Name 3 ways DNA is introduced into mice

Answer 6

1. Retroviral Vectors
2. Microinjection
3. Embryonic Stem Cells

Question 7

Retrovirus

Answer 7

Eukaryotic RNA virus that can form double-stranded DNA copies of their own genome. The ds copies integrate into an infected host cell’s genome.

Question 8

Retroviral Vector Method

Answer 8

1. Embryos infected with transgene containing retrovirus
2. Embryo implanted in female
3. Pups are screened for insertion
4. New lines established from pups with transgene in germ line cells

Question 9

Drawbacks to Retroviral Vector Method

Answer 9

• Applications limited in size (8 kb of DNA)
• Organisms could become carrier of virus if viral genetic content also incorporated
• Rarely used for commercial products

Question 10

DNA Microinjection Method

Answer 10

Preferred Method

• Females are induced to super ovulate (35 eggs rather than 5-10)
• Females are killed and eggs are harvested
• Microinjection occurs immediately in male pronuclei (because it’s larger)
• Implanted in female, pups delivered in 3 weeks
• PCR from tail identifies transgenic offspring
• Mating tests determine if transgene present in germ line

Question 11

Drawbacks to DNA Microinjection Method

Answer 11

Inefficient - at best 5% of eggs become live transgenic animals