Day 2.5 mouse embryos can be aggregated to generate chimera mice. Morula
are collected from superovulated mice. Zona pellucida (outer membrane)
is removed chemically and one denuded embryo from each strain is cultured
overnight in a welled petri dish. The following morning, aggregated embryos
are transferred into pseudopregnant recipients. Offspring are maintained
at GEAM until weaning age, then transferred to the investigator.
GEAM can perform ovarian transplants to rescue lines of mutanted or transgenic
mice that have difficulties breeding or have never generated offspring.
Donor mutanted/transgenic females are moved to the quarantine room at
Biotechnology Center. GEAM will excise the ovaries and transfer them into
two recipient ovariectomized wild-type females (one per recipient). Recipient
females must be strain histocompatible with the donor. Recipients are
housed at GEAM for two weeks to assure recovery from the surgery then transferred
to the investigator for breeding.
Investigators can request recovery of strains at any time. Briefly, the sperm head is microinjected into an unfertilized oocytes from superovulated wildtype females. Resulting fertilized embryos will be transferred into recipients. Offspring will be transferred to the investigator at 3 wks of age, pending serology results and completion of the animal transfer form by the investigator and approval by the veterinarian from the relevant school.