REDERIVATION:
What is Rederivation?
The procedure by which an early, pre-implantation stage embryo is isolated from the reproductive tract of one mouse (donor female) and transferred to the reproductive tract of a mouse (recipient female) made pseudopregnant in order to allow implantation, gestation, and birth. The rederivation procedure consists of collection, in vitro maturation and embryo transplantation.
Purpose:
-To reduce or prevent the potential for transmission of pathogens from a mouse that is being placed in inside a barrier housing facility.
- Embryos can either be harvested from "donor" female mice
- Mated naturally to stud males
- Created by assisted reproduction techniques (IVF).
Procedure:
For heterozygous lines:
- Investigator will provide 5 males (8-20 weeks old)
- Rederivation Core will purchase wild type females (up to 10) from the appropriate background (from a preferred vendor)
For homozygous lines:
- Investigator will provide 5-10 males (3-8 weeks old)
- 10 homozygous females (3 to 6 weeks old)
- Females are superovulated and embryos are collected, pooled, and washed to reduce the risk of pathogen transfer.
- The embryos are surgically transferred, using aseptic technique, into reproductive tract of pseudopregnant recipient females.
- If other recipients are requested, the procedure falls under customized rederivation services.
Steps Involved:
- Rederivation request form - now through RIO.
- Provide documentation where the mice are coming from (defined, conventional, undefined thus indicating that additional safeguards for pathogen removal are necessary).
- Provide males of the appropriate age
- Provide the current mutant of males.
Note: Please inform core of genotyping final results and when to sacrifice the original mice.
The Rederivation Core will:
- Return to investigator at least one rederived litter or a minimum of one breeding pair (SPF health status).
- Provide accurate documentation of matings upon request.
- Rederivation core does not guarantee success.
All movement of mice must be coordinated through the LARC business office as an inter-facility transport. Please click here for the shipping link.
Procedure rates:
- Cost of rederivation by NM: $250
- Cost of egg donors, recipients, and cost of per diem will be recharged to the PI's account.
- The PI has the option to cryopreserve sperm from 2 males used for rederivation at an additional cost of $320 (Click here for Cryo Core Link).
- If more than 5 recipients (2 rederivations) are needed, it will fall under the category of customized rederivation and extra charges may be incurred.
Time line:
Approximately 12-16 week