Response to divergent selection for nesting behavior in Mus musculus

Area of Science:

• Behavioral genetics
• Animal behavior

Background:

• Nest building is a complex behavior in rodents.
• Understanding the genetic basis of behavior is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the heritability of nest-building behavior in Mus musculus.
• To examine correlated responses in other traits during selective breeding.

Main Methods:

• Replicated bidirectional selection for nest building over 15 generations.
• Nesting score measured by cotton weight pulled through cage lid.
• Control lines maintained for comparison.

Main Results:

• An eight-fold difference in nesting scores between high and low lines was achieved.
• Realized heritability was 0.18 +/- 0.02, with variations between high (0.15) and low (0.23) lines.
• Correlated responses included increased body weight and infertile matings, and decreased litter size, though not consistent across all lines.

Conclusions:

• Nest-building behavior in Mus musculus is heritable.
• Selection for nesting behavior can lead to correlated changes in body weight and reproductive fitness.
• Observed changes suggest a complex genetic architecture underlying these traits.