Mmtv-cre

Question 1

What is the effect of global Erbb2 knockout in mice?

Answer 1

Germline knockout of ErbB2 is associated with embryonic lethality.
Mice lacking functional ErbB2 die at embryonic day 10.5 (E10.5) due to cardiac and neural defects.

Question 2

How was the ErbB2 Flox/Flox transgenic mouse generated.

Answer 2

ErbB2 Flox/Flox mouse was generated by knocking in loxP flanked rat ErbB2 cDNA into the first exon of the endogenous mouse ErbB2 gene.

Question 3

Describe the ErbB2 expression and phenotype of ErbB2 Flox/Flox mice.

Answer 3

ErbB2 Flox/Flox mice are viable and exhibit no obvious phenotypic abnormalities. Due to low expression of the ErbB2 cDNA, they express 10% of wild-type ErbB2 but exhibit normal mammary gland development.

Question 4

Why is the MMTV promoter/enhancer used on the FVB background.

Answer 4

The MMTV promoter/enhancer is often methylated in strains other than FVB.

Question 5

What does MMTV LTR stand for?

Answer 5

Mouse mammary tumor virus (MMTV) long terminal repeat (LTR)

Question 6

Describe the MMTV c-myc transgenic mice

Answer 6

MMTV c-myc transgenic mice primarily develop solitary mammary carcinomas that arise in stochastic fashion and appear clonal in origin.

Stochastic = random

Question 7

How is expression regulated under the MMTV LTR?

Answer 7

Expression under the MMTV LTR promoter is induced by glucocorticoids, progesterone, and dihydrotestosterone

Question 8

In which tissues are genes under the MMTV promoter expressed?

Answer 8

MMTV is is almost exclusively expressed in the mammary gland.

Low levels can be detected in salivary glands, lungs, kidneys, and lymphoid tissues.