Which of the following would help maintain genetic integrity when producing axenic pups by hysterectomy derivation?

• A. Use aseptic technique during the hysterectomy procedure
• B. Make sure that all the animals used in the process have the same genetic background
• C. Choose foster mothers whose litter has been weaned and the pups removed
• D. Use a donor female and foster mother with different coat colors

Answer: (D)

Maintaining genetic integrity in axenic pups produced by hysterectomy derivation hinges on clearly distinguishing which pups come from the donor lineage and preventing mix-ups during fostering. Using a donor female and a foster mother with different coat colors provides an immediate visual cue that helps staff correctly attribute each pup to the donor’s genetic background. When the pups are nursing and being recorded, the color contrast makes it easier to verify origin, reducing the chance of misidentifying pups from different genetic lines and thereby preserving the intended genetic makeup for the study.

Aseptic technique is essential for keeping the pups germ-free, but it doesn’t by itself ensure correct genetic attribution. Having all animals share the same genetic background can aid consistency, but it doesn’t address the practical risk of mixing litters or mislabeling pups during fostering. Choosing a foster mother whose litter has been weaned or whose pups have been removed would complicate care and tracking rather than support genetic integrity.