GenPhySE, Université de Toulouse, INRAE, ENVT, 31326, Castanet Tolosan, France.
INRAE, AgroParisTech, GABI, Université Paris Saclay, 78350, Jouy-en-Josas, France.
Genet Sel Evol. 2023 Sep 21;55(1):66. doi: 10.1186/s12711-023-00833-y.
Evolutionary studies have reported that non-genetic information can be inherited across generations (epigenetic marks, microbiota, cultural inheritance). Non-genetic information is considered to be a key element to explain the adaptation of wild species to environmental constraints because it lies at the root of the transgenerational transmission of environmental effects. The "transmissibility model" was proposed several years ago to better predict the transmissible potential of each animal by taking these diverse sources of inheritance into account in a global transmissible potential. We propose to improve this model to account for the influence of the environment on the global transmissible potential as well. This extension of the transmissibility model is the "transmissibility model with environment" that considers a covariance between transmissibility samplings of animals sharing the same environment. The null hypothesis of "no transmitted environmental effect" can be tested by comparing the two models using a likelihood ratio test (LRT).
We performed simulations that mimicked an experimental design consisting of two lines of animals with one exposed to a particular environment at a given generation. This enabled us to evaluate the performances of the transmissibility model with environment so as to detect and quantify transgenerational transmitted environmental effects. The power and the realized type I error of the LRT were compared to those of a T-test comparing the phenotype of the two lines, three generations after the environmental exposure for different sets of parameters. The power of the LRT ranged from 45 to 94%, whereas that of the T-test was always lower than 26%. In addition, the realized type I error of the T-test was 15% and that of the LRT was 5%, as expected. Variances, the covariance between transmissibility samplings, and path coefficients of transmission estimated with the transmissibility model with environment were close to their true values for all sets of parameters.
The transmissibility model with environment is effective in modeling vertical transmission of environmental effects.
进化研究报告称，非遗传信息可以在代际间遗传（表观遗传标记、微生物组、文化传承）。非遗传信息被认为是解释野生动物适应环境限制的关键因素，因为它是环境影响跨代传递的根源。“可传递性模型”是几年前提出的，通过考虑这些不同的遗传来源在整体可传递潜力中的作用，更好地预测每个动物的可传递潜力。我们建议改进该模型，以考虑环境对全球可传递潜力的影响。该可传递性模型的扩展是“带有环境的可传递性模型”，它考虑了具有相同环境的动物的可传递性采样之间的协方差。通过似然比检验（LRT）比较两个模型，可以检验“没有传递的环境效应”的零假设。
我们进行了模拟实验，模拟了一个实验设计，其中两条动物线中的一条在特定的世代中暴露在特定的环境中。这使我们能够评估带有环境的可传递性模型的性能，以便检测和量化跨代传递的环境效应。LRT 的功效和实际的第一类错误与 T 检验进行了比较，该 T 检验比较了两种线在环境暴露后三代的表型差异，针对不同的参数集。LRT 的功效范围从 45%到 94%，而 T 检验的功效始终低于 26%。此外，T 检验的实际第一类错误为 15%，LRT 的实际第一类错误为 5%，符合预期。对于所有参数集，带有环境的可传递性模型估计的传递方差、可传递性采样之间的协方差和传递路径系数都接近其真实值。
带有环境的可传递性模型在模拟环境影响的垂直传递方面是有效的。
