Wang Jing, Lv Xuemin, Feng Li, Dong Ang, Liang Dan, Wu Rongling
National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Departments of Public Health Sciences and Statistics, Center for Statistical Genetics, The Pennsylvania State University, Hershey, PA, United States.
Front Genet. 2022 Jan 28;12:794907. doi: 10.3389/fgene.2021.794907. eCollection 2021.
Testing Hardy-Weinberg equilibrium (HWE) is a fundamental approach for inferring population diversity and evolution, but its application to octoploids containing eight chromosome sets has not well been justified. We derive a mathematical model to trace how genotype frequencies transmit from parental to offspring generations in the natural populations of autooctoploids. We find that octoploids, including autooctolpoids undergoing double reduction, attach asymptotic HWE (aHWE) after 15 generations of random mating, in a contrast to diploids where one generation can assure exact equilibrium and, also, different from tetraploids that use 5 generations to reach aHWE. We develop a statistical procedure for testing aHWE in octoploids and apply it to analyze a real data set from octoploid switchgrass distributed in two ecologically different regions, demonstrating the usefulness of the test procedure. Our model provides a tool for studying the population genetic diversity of octoploids, inferring their evolutionary history, and identifying the ecological relationship of octoploid-genome structure with environmental adaptation.
检验哈迪-温伯格平衡（HWE）是推断种群多样性和进化的基本方法，但其在包含八组染色体的八倍体中的应用尚未得到充分论证。我们推导了一个数学模型，以追踪基因型频率在同源八倍体自然种群中从亲代到子代世代的传递方式。我们发现，八倍体，包括经历双减数的同源八倍体，在随机交配15代后达到渐近哈迪-温伯格平衡（aHWE），这与一代就能确保精确平衡的二倍体不同，也与需要5代才能达到aHWE的四倍体不同。我们开发了一种统计程序来检验八倍体中的aHWE，并将其应用于分析来自分布在两个生态不同区域的八倍体柳枝稷的真实数据集，证明了该检验程序的实用性。我们的模型为研究八倍体的种群遗传多样性、推断其进化历史以及确定八倍体基因组结构与环境适应性的生态关系提供了一个工具。
