Genotypic Frequencies at Equilibrium for Polysomic Inheritance Under Double-Reduction
Genotypic Frequencies at Equilibrium for Polysomic Inheritance Under Double-Reduction
复制标题
双还原下多体遗传平衡的基因型频率
DOI：
10.1534/g3.119.400132
复制
发表时间：
2019-05-01
影响因子：
2.6
通讯作者：
Li, Baoguo
中科院分区：
文献类型：
--
作者：
Huang, Kang;Wang, Tongcheng;Li, Baoguo
多倍体是指其基因组由两组以上的完整染色体组成的生物体。同源多倍体和异源多倍体都可能表现为多体遗传。多体遗传的一个特点是在减数分裂过程中形成多价体，导致双重还原，当姐妹染色单体片段分离到相同的配子时发生。双重减数会导致配子携带完全相同的等位基因，并略微增加纯合性。这将导致基因频率偏离预期值，从而偏离分子生态学和选择育种中使用的标准群体遗传分析方法的结果。在这项研究中，我们扩展了现有的双重还原模型，以解释任何偶数水平的倍性，并通过两种方法推导出基因频率的符号表达式。还计算了双减和近交条件下的近交系数和杂合度。将计算机模拟得到的数值解与模型预测的解析解进行比较，验证了模型的有效性。
Polyploids are organisms whose genomes consist of more than two complete sets of chromosomes. Both autopolyploids and allopolyploids may display polysomic inheritance. A peculiarity of polysomic inheritance is multivalent formation during meiosis resulting in double-reduction, which occurs when sister chromatid fragments segregate into the same gamete. Double-reduction can result in gametes carrying identical-by-descent alleles and slightly increasing homozygosity. This will cause the genotypic frequencies to deviate from expected values and will thus bias the results of standard population genetic analytical methods used in molecular ecology and selective breeding. In this study, we extend existing double-reduction models to account for any even level of ploidy, and derive the symbolic expressions for genotypic frequencies via two methods. Inbreeding coefficients and heterozygosity under double-reduction and inbreeding are also calculated. Numerical solutions obtained by computer simulations are compared with analytical solutions predicted by the model to validate the model.