The genetic basis of maternal behaviour and parent-offspring conflict resolution in mice

在哺乳动物中，母亲提供幼崽发育的资源和早期环境，因此是决定个体表型的最具影响力的因素。个体发育是自身基因型（直接遗传效应）和与母体基因型（间接遗传效应）变异相互作用的结果，后者导致不同的母体行为和母体供给水平。母亲在孩子身上投入多少取决于母亲和子女之间的冲突，因为子女通常会要求比母亲最理想的更多。这种冲突的解决受到后代和母亲基因型的影响，然而，两者的相对重要性尚不清楚。此外，理论假设亲代抚育和后代行为的遗传变异允许两者共同进化，通常导致母亲和后代特征的共同适应，共同产生高后代适合度。如果我们想了解早期发育的遗传基础，以及决定生命早期和成年期表型变异的个体因素，分离后代和母亲基因型的影响是至关重要的。我建议使用简单的交叉培养实验来解决这些问题，在小鼠中测量在自然环境中表现出的与生物学相关的母性行为，后代供应和请求行为作为母性或后代基因型的功能。这将使我能够梳理后代和父母对母亲供给冲突解决的影响，并确定后代和父母特征之间的共同适应程度。拟议的项目将利用重组近交系BXD的小鼠，其基因组标记数据可用于表示野生小鼠种群中发现的遗传变异，并采用已建立的协议来记录表型数据。利用数量性状位点（QTL）作图，我的目标是确定与性状变异相关的基因组区域。该项目的结果将使我们能够确定直接遗传效应（后代基因型）和间接遗传效应（母系遗传效应）对母系投资和母系行为水平的相对贡献。此外，发现调节个体发育的关键母亲行为的特定QTL和候选基因可以为未来旨在确定潜在基因的研究提供信息。

In mammals, mothers provide the resources and early environment in which young develop and are thus the most influential factor determining individual phenotypes. Individual development is the result of own genotype (direct genetic effects) and interactions with maternal genotype (indirect genetic effects) variation in which causes different maternal behaviours and levels of maternal provisioning. How much mothers invest in their young is subject to a conflict between mother and offspring where offspring will typically demand more than is optimal for the mother. The resolution of this conflict is affected both by offspring and maternal genotype, however, the relative importance of the two remains unclear. Furthermore, theory assumes genetic variation for both parental care and offspring behaviour to allow the coevolution of the two, often leading to coadaptation of maternal and offspring traits that jointly yield high offspring fitness. Separating the effect of offspring and maternal genotype is crucial if we want to understand the genetic basis for early development and the individual factors that determine variation in phenotypes early in life but also in adulthood. I propose to address these issues using simple cross-fostering experiments in mice measuring biologically relevant maternal behaviours that are exhibited in natural environments, offspring provisioning and solicitation behaviour as a function of either maternal or offspring genotype. This will enable me to tease apart offspring and parental influences on conflict resolution over maternal provisioning and to determine the degree of coadaptation between offspring and parental traits. The proposed project will utilise mice of the recombinant inbred strain BXD, for which genomic marker data are available representing genetic variation found in wild populations of mice and employing established protocols to record phenotypic data. Using quantitative trait loci (QTL) mapping, I aim to identify regions of the genome that correlate with trait variation. The results of the project will enable us to ascertain the relative contribution of direct genetic effects (offspring genotype) and indirect genetic effects (maternal genetic effects) on the level of maternal investment and maternal behaviours. Furthermore, finding specific QTL and candidate genes for key maternal behaviours that modulate individual development can inform future research aiming to identify the underlying genes.