Data from: XY females do better than the XX in the African pygmy mouse, Mus minutoides

All therian mammals have a similar XY/XX sex determination system except for a dozen species. The African pygmy mouse, Mus minutoides, harbors an unconventional system in which all males are XY, and there are three types of females: the usual XX but also XX* and X*Y ones (the asterisk designates a sex reversal mutation on the X chromosome). The long-term evolution of such a system is a paradox, since X*Y females are expected to face high reproductive costs (e.g. meiotic disruption and loss of unviable YY embryos), which should prevent invasion and maintenance of a sex-reversal mutation. Hence, mechanisms for compensating for the costs could have evolved in M. minutoides. Data gathered from our laboratory colony revealed that X*Y females do compensate and even show enhanced reproductive performance in comparison to the XX and XX*; they produce significantly more offspring due to (i) a higher probability of breeding, (ii) an earlier first litter, and (iii) a larger litter size, linked to (iv) a greater ovulation rate. These findings confirm that rare conditions are needed for an atypical sex determination mechanism to evolve in mammals, and provide valuable insight into understanding modifications of systems with highly heteromorphic sex chromosomes.Kinship matrixKinship matrix used as a correlation structure to describe relatedness between females in the statistical models.kinship_matrix.csvfemale_dataData about all females that were raised in the lab colony: genotype, date of birth, age at contact, overall progeny number, first litter age, mean litter size, mean interbirth interval...corpora_lutea_count_dataCorpora lutea count for all females dissected to estimate the ovulation rate.Contains information on female identity, genotype, corpora lutea count and age of female at the time of the dissection.Full_pedigreeThe full pedigree of all individuals (females and males) considered in the study, along with their genotype and the identity of both maternal and paternal chromosomes.pedigree_full.cs