Dummerstorf high fertility mouse lines are selected for increased fertility. After ~200 generations they doubled their ovulation rate and litter size. This worldwide unique lines can give some insides into the desired highly-informative phenotype of high-fertility, in which those peculiarities of enhanced reproductive performance coexist with characteristics that the literature mostly correlates with a lowering of fertility. The deep analysis of FLs can be a very informative way to get the methods they use to avoid their "bad" characteristics to have an impact in their higher-fertility traits.<eng>
