Genetic interaction between a maternal factor and the zygotic genome controls the intestine length in PRM/Alf mice

1 UMR 955 INRA-ENVA de Génétique Moléculaire et Cellulaire, Ecole Nationale Vétérinaire d’Alfort, 94704 Maisons-Alfort cedex, France 2 Unité de Génétique des Mammifères, Institut Pasteur, 75724 Paris cedex 15, France Postoperative management of small and large bowel resections would be helped by use of intestinotrophic molecules. Here, we present a mouse inbred strain called PRM/Alf that is characterized by a selective intestinal lengthening. We show that PRM/Alf intestine is one-third longer compared with other inbred strains. The phenotype is acquired mostly during the postnatal period, before weaning. Its genetic determinism is polygenic, and involves a strong maternal effect. Cross-fostering experiments revealed that the dam’s genotype acts synergistically with the offspring’s genotype to confer the longest intestine. Moreover, genes in the offspring have a direct effect on intestine length. Possible involvement of milk growth factors and identification of candidate genes are discussed. inbred strains; mouse; genotype-environment interaction; organ development; gut adaptation