No speed dating please! Patterns of social preference in male and female house mice

Background: In many animal species, interactions between individuals of different sex often occur in the context
of courtship and mating. During these interactions, a specific mating partner can be chosen. By discriminating
potential mates according to specific characteristics, individuals can increase their evolutionary fitness in terms of
reproduction and offspring survival. In this study, we monitored the partner preference behaviour of female and
male wild house mice (Mus musculus domesticus) from populations in Germany (G) and France (F) in a controlled
cage setup for 5 days and six nights. We analysed the effects of individual factors (e.g. population origin and sex)
on the strength of preference (selectivity), as well as dyadic factors (e.g. neutral genetic distance and major
histocompatibility complex (MHC) dissimilarity) that direct partner preferences.
Results: Selectivity was stronger in mice with a pure population background than mixed individuals. Furthermore,
female mice with a father from the German population had stronger selectivity than other mice. In this group, we
found a preference for partners with a larger dissimilarity of their father’s and their partner’s MHC, as assessed by
sequencing the H2-Eß locus. In all mice, selectivity followed a clear temporal pattern: it was low in the beginning
and reached its maximum only after a whole day in the experiment. After two days, mice seemed to have chosen
their preferred partner, as this choice was stable for the remaining four days in the experiment.
Conclusions: Our study supports earlier findings that mate choice behaviour in wild mice can be paternally influenced.
In our study, preference seems to be potentially associated with paternal MHC distance. To explain this, we propose
familial imprinting as the most probable process for information transfer from father to offspring during the offspring’s
early phase of life, which possibly influences its future partner preferences. Furthermore, our experiments show that
preferences can change after the first day of encounter, which implies that extended observation times might be
required to obtain results that allow a valid ecological interpretation.

研究背景：在众多动物物种中，不同性别的个体间互动常发生于求偶与交配情境中。在此类互动过程中，个体可选择特定的交配伴侣。通过依据特定特征甄别潜在配偶，个体能够提升自身在繁殖与后代存活层面的进化适合度。本研究于受控笼养环境中，对源自德国（G）与法国（F）种群的野生小家鼠（Mus musculus domesticus）雌雄个体的伴侣偏好行为开展了为期5天6夜的监测。我们分析了个体因素（如种群来源与性别）对偏好强度（即选择性）的影响，以及调控伴侣偏好的二元因素（如中性遗传距离与主要组织相容性复合体（MHC）差异度）。
研究结果：种群背景为纯种的小鼠，其选择性强于混血个体。此外，父亲源自德国种群的雌性小鼠，其选择性相较于其他小鼠更为显著。在该组小鼠中，我们发现其偏好父亲与伴侣MHC差异度更高的配偶，该结论通过对H2-Eß基因座的测序得以验证。在所有受试小鼠中，选择性均呈现清晰的时间模式：实验初期选择性较低，仅在实验进行满一日后才达到峰值。实验进行两日之后，小鼠似乎已选定偏好的伴侣，该选择在后续的四天实验周期中保持稳定。
研究结论：本研究支持此前的相关发现，即野生小鼠的配偶选择行为可受父系影响。在本研究中，伴侣偏好似乎与父系MHC距离存在潜在关联。为解释该现象，我们提出，家族印记是后代生命早期阶段父亲向后代传递信息的最可能过程，该过程或可影响后代未来的伴侣偏好。此外，本实验表明，伴侣偏好可在初次接触一日后发生变化，这意味着若要获得可进行有效生态学解读的实验结果，可能需要更长的观察时长。