Infanticide: accounting for genetic variation in mice

Area of Science:

• Behavioral Neuroscience
• Genetics
• Endocrinology

Background:

• Infanticide in mice is a sexually dimorphic behavior influenced by androgens.
• Significant genetic variation exists in infanticide levels between mouse strains (e.g., C57BL/6J vs. DBA/2J).

Purpose of the Study:

• To investigate the factors contributing to strain differences in male mouse infanticide.
• To determine if social factors or hormonal differences explain infanticide variation.

Main Methods:

• Comparative analysis of infanticide behavior across different mouse strains.
• Assessment of postweaning social interactions.
• Measurement of perinatal, pubertal, and adult circulating hormone levels.

Main Results:

• Strain differences in infanticide were not correlated with postweaning social factors.
• No significant differences in perinatal, pubertal, or adult hormone levels were found between strains.
• Results suggest genetic factors, potentially interacting with prenatal hormone exposure or sensitivity, underlie behavioral differences.

Conclusions:

• Strain-specific infanticide in mice is not explained by social environment or adult hormone levels.
• Genetic predisposition, possibly involving prenatal hormonal milieu and sensitivity, is a key determinant.
• A model is proposed for gene-hormone interactions in sexually dimorphic behaviors.