A multivariate quantitative-genetic analysis of behavioral development in mice

Area of Science:

• Behavioral genetics
• Developmental biology
• Mouse models

Background:

• Understanding the genetic basis of early behavioral development is crucial.
• Behavioral ontogeny in mice involves complex genetic architectures.
• Previous studies have not fully elucidated the multivariate genetic structure of early behaviors.

Purpose of the Study:

• To perform a behavior-genetic dissection of early behavioral development in laboratory mice.
• To uncover the genetical architecture and multivariate genetic structure of early behavioral ontogeny.
• To investigate genetic influences on the timing of sensorimotor development.

Main Methods:

• Utilized a full, replicated diallel cross involving five inbred mouse strains.
• Administered standard sensorimotor tests to 622 pups across multiple postnatal days (3-22).
• Employed multivariate analysis of variance (MANOVA) and Hayman's analysis of variance for diallel tables.

Main Results:

• No significant effect of pup sex on the speed of development was observed.
• Additive-genetic effects were minimal; dominance was largely absent, except for weak directional dominance in auricular startle response.
• Factor analyses indicated at least two factors are necessary to describe behavioral variation.

Conclusions:

• Results suggest a history of directional selection for well-canalized development.
• Genetic factors influencing early behavioral ontogeny are complex, with limited additive or dominant effects.
• Behavioral variation is likely driven by multiple underlying genetic factors.