Q21. Mouse Breeding Basics

How much do you know about mouse breeding?   Might be useful one day to know a few fun facts!
Here are some questions you ought to know the answer to.... (and if you forgot - links to useful online references are provided)





1.  Mouse pups: at what age does...

• The milk spot disappear
• Hair first appear
• Ears start to come away from head
• Teeth erupt
• Eyes are fully open
• Eat solid food

Check HERE if you need a reminder

2.  Timed breeding.  How would you time breeding without the use of drugs?   ( there are good summaries HERE  and HERE)

3.  If you need to superovulate to produce many eggs (eg for embryo freezing) the protocol is...

• Take group housed female mice aged _______ days
• Inject 2-5 IU PMSG between ___________(time of day) on day 1.
• Inject 2-5 IU HCG ________   hours later on day _____
• Mate with stud (8 weeks old individually housed)_____________(when?)
• Ovulation occurs __________ hours later.

(And HERE is the protocol)

4.  Estrus Cycle: visual external characteristics (ie vaginal opening appearance) 

• What distinguishes proestrus from estrus? 
• Metestrus from Diestrus?

5. Estrus Cycle: Vaginal smears - 

• What distinguishes proestrus from estrus? 
• Metestrus from diestrus?

A really nice review for questions 4 and 5 can be found HERE

6. Early Pregnancy Diagnosis

• Ultrasound can identify pregnancy as early as Embryonic Day ___  (assuming day following mating is Day 0.5)  Reference 
• Weight change can identify pregnancy as early as day ED_____   Reference

And here are a few easy ones...

7. Delayed implantation generally occurs when ________________________________ 

8. For breeding, always add the female/male to the female/male's cage

9. Gestation generally lasts between ___ and ____ days

10. B6 mouse pups should weigh approximately _____grams on weaning at 3 weeks.


ANSWERS are posted HERE