Sibling sex, but not androgens, shapes phenotypes in perinatal common marmosets (Callithrix jacchus).

摘要: When offspring share a womb, interactions among fetuses can impart lasting impressions on phenotypic outcomes. Such intrauterine often are mediated by sex steroids (estrogens and androgens) produced the developing fetuses. In many mammals, between brothers sisters lead to masculinization of females, which induce fitness consequences. Many litter-bearing primates, though, seem escape androgen-mediated litter effects, begging why? Here, we investigated how composition (i.e., same- or mixed-sex) litters influences perinatal outcomes in common marmoset monkey (Callithrix jacchus), using combination physiological, morphological, behavioural assays. We hypothesized that androgens from male would mediate developmental differences across types. found newborns (24–36 hours old) mixed-sex were indistinguishable urinary androgen profiles, birth weights, morphometrics, behaviour. However, monkeys born into exhibited subtle morphological neurobehavioral later period, independent their profiles. Our findings suggest while likely do not organize siblings’ phenotypes, stimuli may initiate divergent trajectories siblings, which, turn, promotes inter-individual variability within families.