The mutation load under tetrasomic inheritance and its consequences for the evolution of the selfing rate in autotetraploid species
The mutation load under tetrasomic inheritance and its consequences for the evolution of the selfing rate in autotetraploid species
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四体遗传下的突变负荷及其对同源四倍体物种自交率进化的影响
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
J. Ronfort
中科院分区：
文献类型：
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作者：
J. Ronfort
在突变选择平衡模型下，推导了部分自交同源四倍体群体中部分隐性有害突变的单位点平衡频率。假设基因座之间的乘法健身相互作用，平均健身和近交衰退值的近似解决方案也来自多个基因座的情况下，并与二倍体模型的预期相比。与二倍体一样，同源四倍体群体也会通过近亲交配清除有害突变，即平衡突变负荷是自交率的递减函数。然而，近交衰退随自交率的变化在很大程度上取决于与三种杂合基因型相关的优势系数。近交衰退随自交率的增加而增加或减少，并不总是单调变化的。因此，预期的自交率的演变问题取决于优势系数。在某些情况下，期望的自交率的演变类似于二倍体的期望，但特定的优势系数集可以发现，导致完全自交或中间自交率作为唯一的进化稳定状态。
Single-locus equilibrium frequencies of a partially recessive deleterious mutation under the mutation–selection balance model are derived for partially selfing autotetraploid populations. Assuming multiplicative fitness interactions among loci, approximate solutions for the mean fitness and inbreeding depression values are also derived for the multiple locus case and compared with expectations for the diploid model. As in diploids, purging of deleterious mutations through consanguineous matings occurs in autotetraploid populations, i.e. the equilibrium mutation load is a decreasing function of the selfing rate. However, the variation of inbreeding depression with the selfing rate depends strongly on the dominance coefficients associated with the three heterozygous genotypes. Inbreeding depression can either increase or decrease with the selfing rate, and does not always vary monotonically. Expected issues for the evolution of the selfing rate consequently differ depending on the dominance coefficients. In some cases, expectations for the evolution of the selfing rate resemble expectations in diploids; but particular sets of dominance coefficients can be found that lead to either complete selfing or intermediate selfing rates as unique evolutionary stable state.