A Berkshire X Yorkshire three-generation population from a quantitative trait loci (QTL) study was used to determine whether identical twin births occurred in pigs. The population consisted of 65 families with 525 F2 individuals. Genotype data at 125 microsatellite marker loci were examined for all F2 animals. One pair of female twins was found in the population. This is a unique result because there have been no published reports to date of twin births in pigs. In addition, three mutations of the microsatellite markers used in the QTL study were discovered out of the 134,565 meioses that occurred. This gives an overall mutation rate for the population of 2.23 X 10-5. This mutation rate is similar to previously published data.
Iowa State University
Grapes, L.; Malek, M.; and Rothschild, M. F., "Identification of Identical Twins and Mutation rate in pigs" (2001). Swine Research Report, 2000. 23.