Data used for "Contribution of host-specific microbiota to host fitness revealed by a microbiota transplantation experiment among the genotypes of an asexual animal species"

To test whether host animals regulate genetically their microbiota to enhance fitness, we transplanted microbiota between two genetically distinct genotypes of obligate parthenogenetic <i>Daphnia cf. pulex</i>, each harboring different microbial communities. Sterilized individuals were inoculated with microbiota from either the same or a different genotype, and their growth, reproduction, and microbiota composition were examined. Growth and reproduction were greater when individuals received microbiota from their own genotype than from another, indicating that <i>Daphnia</i> maintain genotype-specific microbiota that enhance fitness. However, the effects of microbiota inoculation varied with genotype and food availability. In addition, although overall microbial composition differed consistently between genotypes regardless of the different bacterial inoculations, these differences were not directly related to host performance. These results showed that host animals can constrain genetically at least some part of microbiota composition and that functionally important, numerically minor bacteria may drive genotype-specific differences in host fitness.