Hadsell1 project protocol

Maternal nurturing in 31 inbred strains of mice   (2012)

Hadsell DL
With: Wei J, Olea W, Hadsell LA, Renwick A, Thomson PC, Shariflou M, Williamson P

Hadsell1 Protocol

Project protocol - Contents

Workflow and sampling

Data collected
Matings set up between males and females of each strain (litter 1)
Females allowed to complete first lactation (litter 1)
3 Females treated with gonadotropin and mated with CD-1 males (litter 2) -
4 Biological pups counted (litter 2) and replaced with ten CD-1 pups (cross-foster litter) Cross-foster litter weight and number of surviving pups recorded daily for each female through day 8 postpartum

Equipment and supplies

  • Funnel feeders (Research Products International, Mt. Prospect IL)
  • Nestlet pads (Ancare, Bellmore NY)

Reagents and solutions

  • Pregnant Mare Serum Gonadotropin (PMSG)
  • Human Chorion Gonadotropin (hCG)

Procedure: Mating, cross-fostering, and monitoring

    1. Mice are maintained on 2020X pelleted food (Harlan Teklad) except where noted.
    2. Matings are set up between males and females of each strain to allow all females to complete one lactation (litter 1).
    3. Females are given 2.5 IU of Pregnant Mare Serum Gonadotropin (PMSG) i.p. at noon followed by 2.5 IU of Human Chorionin Gonadotropin (hCG) i.p. 46 hours later.
    4. Immediately after the hCG injection, females of each inbred strain are mated to CD-1 males (litter 2). Note that CD-1 females and CD-1 males are mated at the same time to produce litters for cross-fostering.
    5. At day 15 of pregnancy, females from inbred strains are switched to a powdered form of AIN-93G (Harlan Teklad) dispensed in funnel feeders.
    6. Each female is given a single nestlet pad on day 15 of pregnancy to provide standardized material for nest building.
    7. On day 1 postpartum, the number of pups born to each inbred female is recorded (litter 2).
    8. Biological pups (litter 2) are removed from the cage on day 1 and replaced with ten neonatal (day 1) CD-1 pups (cross-foster litters are adjusted so that all have similar weight).
    9. Litter weights and surviving pup numbers are recorded daily through day 8 postpartum.

Data collected by investigator

  • Number of biological pups born (litter 2, from CD-1 sire)
  • Average daily cross-fostered litter gain (calculated daily based on litter size)
  • Number of cross-fostered pups surviving to day 8