Data from: Maternal-fetal genomic conflict and speciation: no evidence for hybrid placental dysplasia in crosses between two house mouse subspecies
Kropáčková, Lucie et al. (2015), Data from: Maternal-fetal genomic conflict and speciation: no evidence for hybrid placental dysplasia in crosses between two house mouse subspecies, Dryad, Dataset, https://doi.org/10.5061/dryad.3v321
Interspecific hybridization between closely related mammalian species, including various species of the genus Mus, is commonly associated with abnormal growth of the placenta and hybrid fetuses, a phenomenon known as hybrid placental dysplasia (HPD). The role of HPD in speciation is anticipated but still poorly understood. Here we studied placental and fetal growth in F1 crosses between four inbred mouse strains derived from two house mouse subspecies, Mus musculus musculus and M. m. domesticus. These subspecies are in the early stage of speciation and still hybridize in nature. In accordance with the maternal-fetal genomic conflict hypothesis we found different parental influences on placental and fetal development, with placental weight most affected by the father's body weight, and fetal weight by the mother's body weight. After removing the effects of parents’ body weight, we did not find any significant differences in fetal or placental weights between intra-subspecific and inter-subspecific F1 crosses. Nevertheless, we found that the variability in placental weight in inter-subspecific crosses is linked to the X chromosome, similarly as for HPD in interspecific mouse crosses. Our results suggest that maternal-fetal genomic conflict occurs in the house mouse system, but has not yet diverged sufficiently to cause abnormalities in placental and fetal growth in inter-subspecific crosses. HPD is thus unlikely to contribute to speciation in the house mouse system. However, we cannot rule out that it might have contributed to other speciation events in the genus Mus, where differences in the levels of polyandry exist between the species.