Which observation can be used to ensure the integrity of a particular strain of animal?

• A. Strain breeding performance
• B. Coat color of offspring
• C. PCR genotype testing
• D. All of the above

Answer: (D)

Maintaining strain integrity relies on gathering evidence from multiple angles rather than relying on a single observation. Coat color can indicate some genetic background, but it isn’t a definitive proof of identity because color can vary with environment, background genetics, or rare mutations. Breeding performance shows that the colony is reproducing and transmitting the intended traits across generations, supporting stability, yet it alone doesn’t confirm exact genetic identity. PCR genotype testing provides direct confirmation of the strain’s genetic markers, helping detect misidentification or contamination even when outward traits look similar.

Using all of these together gives a robust check: phenotypic traits like coat color, reproductive performance, and molecular genotyping together give a more complete picture of strain integrity and help guard against drift or mix-ups.