[22] Cre-Lox Molecular Mechanism

Question 1

What is the role of Cre Recombinase Enzyme?

Answer 1

Identifies and binds to LoxP sites.

Question 2

What does Cre recombinase do to DNA topology?

Answer 2

Induces a topological change, facilitating recombination.

Question 3

What activities does the Cre enzyme catalyze?

Answer 3

• Cuts at LoxP sites
• Ligase activity to rejoin ends

Question 4

Define Cre Recombinase Enzyme.

Answer 4

Cornerstone of the recombination process.

Question 5

Initials - Cre

Answer 5

Causes Recombination

Question 6

Initials - LoxP

Answer 6

Locus of X-over P1

Question 7

What is Excision in Cre-Lox recombination?

Answer 7

Deletion of DNA between LoxP sites in the same orientation.

Question 8

What is Inversion in Cre-Lox recombination?

Answer 8

Flipping of DNA between LoxP sites in opposite orientations.

Question 9

What is Translocation in Cre-Lox recombination?

Answer 9

Movement of chromosomal segments between different chromosomes.

Question 10

What makes the Cre-Lox system conditional?

Answer 10

Cre activation under specific conditions like drug presence or developmental stage.

Question 11

How is conditionality usually achieved?

Answer 11

Placing Cre under inducible or tissue-specific promoter.

Question 12

How efficient is the Cre-Lox process?

Answer 12

Highly efficient.

Question 13

What are the limitations of Cre-Lox efficiency?

Answer 13

Some cells may escape recombination.

Question 14

What does the Cre-Lox system allow for?

Answer 14

• Temporal control
• Spatial control

Question 15

What is the consequence of Cut and Ligase Activity?

Answer 15

Excision of DNA sequence flanked by LoxP sites.

Question 16

What is the primary limitation of Cre-Lox?

Answer 16

Not always 100% efficient.