An improved transmissibility model to detect transgenerational transmitted environmental effects.

Area of Science:

• Evolutionary biology
• Quantitative genetics
• Animal breeding

Background:

• Non-genetic information (epigenetic marks, microbiota, cultural inheritance) plays a role in transgenerational inheritance.
• This non-genetic inheritance is key for wild species adaptation to environmental changes.
• Existing transmissibility models predict animal breeding potential but do not fully account for environmental influences.

Purpose of the Study:

• To extend the transmissibility model to incorporate environmental effects on inherited traits.
• To introduce the "transmissibility model with environment" accounting for shared environmental covariance.
• To test the null hypothesis of no transmitted environmental effect using a likelihood ratio test (LRT).

Main Methods:

• Simulations were conducted using a two-line animal experimental design with one line exposed to a specific environment.
• The performance of the "transmissibility model with environment" was evaluated for detecting and quantifying transgenerational environmental effects.
• The LRT was compared against a T-test for power and Type I error rates.

Main Results:

• The LRT demonstrated high power (45-94%) in detecting transgenerational environmental effects, significantly outperforming the T-test (<26%).
• The LRT maintained a 5% Type I error rate, aligning with expectations, while the T-test showed a 15% Type I error.
• Estimated variances, covariance, and path coefficients in the enhanced model closely matched true values.

Conclusions:

• The "transmissibility model with environment" is a powerful and effective tool for modeling the vertical transmission of environmental effects.
• This model provides a more accurate prediction of inherited traits influenced by environmental factors across generations.