There are no mice that carry the transgene.

You: Since there are no bands on the gel, it seems to me that there are no transgenic mice in the litter.

Dr. Demetriou: It is a possibility. However, the genetic transmission rate of the transgene, when both parents carry the transgene, is very high. It is quite unlikely that there are no transgenic mice in the litter. What is a more likely explanation for these results?