Genetic Influences on Maternal Care

Abstract: The basis of social evolution in mammals is the mother‐offspring relationship. It is also the primary and most important instance of indirect genetic effects, where genetic variation in one individual affects phenotypic variation among others. This relationship is so important in mammals that often the major factor determining the life or death of newborns is the environment provided by their mother. Variations in these environments can be due to variations in maternal genotypes. In our work with the intercross of two mouse inbred strains, LG/J and SM/J, we uncovered a very severe variation in maternal performance. These females failed to nurture their offspring and showed abnormal maternal behaviors leading to loss of their litter. Rather than this being due to a single gene variant as in knockout mice, we uncovered a complex genetic basis for this trait. The effects of genes on maternal performance are entirely context dependent in our cross. They depend on the alleles present at the same or o...