[21] Cre-Lox System

Question 1

What is Cre Recombinase?

Answer 1

An enzyme from bacteriophage P1 that catalyzes recombination between LoxP sites.

Question 2

Define LoxP sites.

Answer 2

34-base pair DNA sequences targeted by Cre recombinase.

Question 3

Initials - Cre

Answer 3

Causes Recombination

Question 4

Initials - LoxP

Answer 4

Locus of X-over P1

Question 5

What is a floxed gene?

Answer 5

A gene flanked by LoxP sites.

Question 6

What happens when Cre is expressed in a cell?

Answer 6

Excises the floxed gene, deactivating it.

Question 7

Types of recombination possible in Cre-Lox?

Answer 7

• Deletion
• Inversion
• Translocation

Question 8

How is Cre expression often controlled?

Answer 8

• Inducible promoters
• Tissue-specific promoters

Question 9

What does temporal and spatial control mean in the context of the Cre-Lox system?

Answer 9

Targeted gene modification at specific times or in specific cell types.

Question 10

What is Conditional Gene Knockout?

Answer 10

Deleting genes in specific tissues or developmental stages.

Question 11

What is Lineage Tracing?

Answer 11

Marking cells to follow their fate over time.

Question 12

What is meant by Overexpression & Activation in Cre-Lox?

Answer 12

Inserting a floxed STOP cassette before a gene, removable by Cre for gene activation.

Question 13

What does the Cre-Lox system allow researchers to study?

Answer 13

Functional roles of specific genes and cells in mice.

Question 14

In which organism is the Cre-Lox system commonly used?

Answer 14

Mice