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Published on: April 2, 2020
Refining timed pregnancies in two strains of genetically engineered mice
Sarah L Mader1, Nicole L Libal, Kathleen Pritchett-Corning
1Oregon Health and Science University, Department of Anesthesiology and Perioperative Medicine, Portland, OR, USA.
Lab Animal
|August 25, 2009
Summary
Body weight changes after mating are a more reliable indicator of pregnancy in genetically engineered mouse colonies than vaginal plug detection. This finding aids in efficiently producing timed pregnant mice for research.
Area of Science:
- Animal Science
- Reproductive Biology
- Genetics
Background:
- Efficiently generating genetically engineered mouse (GEM) fetuses or neonates requires strain-specific breeding strategies.
- Reliable early pregnancy detection is crucial for accurately timing deliveries and obtaining specific age ranges of offspring.
Purpose of the Study:
- To identify the most accurate early pregnancy indicator in two GEM colonies.
- To establish a reliable and cost-effective method for producing timed pregnant females between gestation days 16 and 18.
Main Methods:
- Evaluated pregnancy indices including pregnancy rate, plug rate, pregnant plugged rate, litter size, and body weight.
- Assessed homozygous soluble epoxide hydrolase knockout (sEHKO) and L7-tau-green fluorescent protein (GFP) transgenic mouse colonies.
- Monitored body weight changes at 1 and 2 weeks post-mating.
Main Results:
- Increases in body weight at 1 and 2 weeks after male exposure were more consistent indicators of pregnancy than vaginal plug detection in both sEHKO and GFP colonies.
- Body weight monitoring offers a more reliable method for pregnancy detection in these GEM lines.
Conclusions:
- Body weight gain is a superior indicator for early pregnancy detection in genetically engineered mice compared to traditional plug checks.
- Refined protocols based on these findings will enhance the efficiency of timed pregnancies in GEM breeding programs.
