Results of pairing experimental males to homozygous wild type 6N females for 10–14 days.

1Females paired with Tgm4 knockout males (KO) gave birth to litters significantly less frequently than when paired with males carrying at least one functional Tgm4 copy (+). (χ2 = 7.934, P = 0.005).2The number of male and females paired for 10–14 days. To control for maternal experience, any pairings that occurred prior to a female's first successful litter were excluded.3Of attempted pairings, the number that resulted in a litter born.4Of attempted pairings, the number that resulted in a weaned litter 21–28 days after birth. Of litters born, there was no significant difference in the number of litters that reached weaning (χ2 = 0.94, P = 0.3).