Recombinant-inbred strains: general methodological considerations relevant to the study of complex characters

Area of Science:

• Genetics
• Animal Behavior
• Quantitative Genetics

Background:

• Recombinant-inbred (RI) strains are valuable for dissecting genetic correlations in complex traits.
• Environmental factors, such as litter effects and maternal influences, are often confounded with genetic effects in RI strain studies.
• The reliability of RI strain means is crucial for accurate genetic analyses.

Purpose of the Study:

• To highlight the importance of environmental influences on RI strain means.
• To provide methods for assessing and controlling for environmental variation.
• To emphasize the utility of RI strains for genetic correlational analyses and gene mapping.

Main Methods:

• Controlling for litter effects by sampling from multiple litters.
• Assessing maternal influences through fostering procedures.
• Estimating the reliability of RI strain means.
• Repeated testing of animals to minimize day-to-day variation in behavioral assays.

Main Results:

• Environmental factors can significantly impact RI strain means, confounding genetic interpretations.
• Appropriate experimental designs can mitigate environmental influences, enhancing the reliability of strain means.
• Reliability estimation provides valuable data for gene mapping and genetic correlation studies.
• RI strains are emerging as a powerful tool for bio-behavioral research beyond traditional gene mapping.

Conclusions:

• Users of RI strains should implement strategies to control for environmental variation, particularly litter and maternal effects.
• Reliability of RI strain means is a critical consideration for accurate genetic correlational analyses and gene mapping.
• RI strains offer a robust methodology for exploring complex trait relationships in the bio-behavioral sciences.