Mouse Colony Expansion


General Description


This service provides investigators with age-matched GEM models for their experiments. The complexity of current GEM models requires the maintenance of large breeding colonies and considerable time to acquire the appropriate number of mice for experiments. The GERM Core will utilize superovulation and embryo transfer to provide Investigators with the required numbers of mice of specific genotypes necessary for their experiments.

What Will Happen

  1. Investigator will submit a request form through iLabs, filling out detail information on male and female mouse numbers and ages. An account and IACUC number must be provided at this time. The Investigator IACUC protocol must be approved for all procedures performed in the user laboratory.
  2. The core will review investigator provided information and approve the request. The core will schedule the colony expansion according to the female mouse age and coordinate with the investigator.
  3. Investigators will complete steps 3-10.  Investigator prepares 8-10 adult males and 8-10 young female mice at age of 3-5 weeks with appropriate genotypes.
  4. One week before the scheduled service date, pick up 1 tube of M2 media, 1 tube of PMSG, and 1 tube of HCG from the GERM Core. Note: Bring an ice bucket to put the hormones in and put them in a -20C freezer when you get back to your lab. Dilute the hormones right before you go to give the injections.
  5. PMSG is given at 10 a.m. three days before the scheduled rederivation date (e.g. Tuesday for procedure on Friday). Dilute the PMSG with 950 ul of 0.9% saline and administer 0.1cc, i.p. per mouse.
  6. HCG is given 47 hours after PMS at 9 a.m., one day before the scheduled rederivation date (e.g. Thursday for procedure on Friday). Dilute the HCG with 950 ul of 0.9% saline and administer 0.1cc, IP per mouse.
  7. Place the females with the males immediately after administering HCG.
  8. The morning following the HCG injections, the females are removed from the male cages and oviducts are collected into M2 media provided by the GERM Core (a protocol will be provided).
  9. Label the tubes with the request number generated by iLab. Deliver the oviducts to R119A in the ABBR and leave in the biosafety hood no later than 9 a.m.
  10. The core will dissect, digest, and collect all oocytes from the oviducts, identify and transfer fertilized 1-cell embryos to pseudo pregnant ICR females to allow gestation.
  11. Live-born founder animals will be held by the GERM Core until 10-14 days of age and subsequently transferred to the User Investigator.

What is Expected

  1. The GERM core will transfer about 150 embryos if available to 10 of 0.5-day pseudo pregnant recipient mice.
  2. This approach will ensure that the Investigator receives 60-80 mice for experimental purposes.