Uncovering sources of maternal variability: Inherited and environmental contributions to maternal phenotype

Intergenerational patterns of parental behavior, especially maternal behavior, have been observed across mammalian species including humans, non-human primates, and rodents. These patterns are largely experience-dependent as opposed to genetically induced, with experiences in early-life serving an essential role in directing maternal behavior expressed later in life. Environmental conditions can also alter maternal behavior with consequences for offspring neurodevelopment and interactions with the next generation. Here, we describe effects of lineage during developmental environmental disruption using a limited bedding and nesting material manipulation during the first 2 weeks of life. Dams from three lineages were placed in environments containing either abundant nesting material or reduced nesting material. Environmental condition affected eight measures of maternal behavior and dam lineage affected 12 measures of maternal behavior during the first two postnatal weeks. Lineage, condition, and pup sex predicted pup body weight immediately following the manipulation, with lineage accounting for the largest portion of variance in body weight. Although from a limited sample, these data are the first to examine effects of lineage and environment simultaneously and suggest dam lineage may be a better predictor of maternal behavior than current environmental conditions with important implications for pup outcomes.