Glémin Sylvain
UMR , CC63 Bat 24, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier, France.
Genet Res. 2005 Aug;86(1):41-51. doi: 10.1017/S0016672305007676.
The fate of lethal alleles in populations is of interest in evolutionary and conservation biology for several reasons. For instance, lethals may contribute substantially to inbreeding depression. The frequency of lethal alleles depends on population size, but it is not clear how it is affected by population structure. By analysing the case of the infinite island model by numerical approaches and analytical approximations it is shown that, like population size, population structure affects the fate of lethal alleles if dominance levels are low. Inbreeding depression caused by such alleles is also affected by the population structure, whereas the mutation load is only weakly affected. Heterosis also depends on population structure, but it always remains low, of the order of the mutation rate or less. These patterns are compared with those caused by mildly deleterious mutations to give a general picture of the effect of population structure on inbreeding depression, heterosis, and the mutation load.
致死等位基因在种群中的命运在进化生物学和保护生物学领域备受关注,原因如下。例如,致死基因可能对近亲繁殖衰退有重大影响。致死等位基因的频率取决于种群大小,但目前尚不清楚它如何受种群结构影响。通过数值方法和解析近似分析无限岛屿模型的情况,结果表明,与种群大小一样,如果显性水平较低,种群结构会影响致死等位基因的命运。此类等位基因引起的近亲繁殖衰退也受种群结构影响,而突变负荷仅受到微弱影响。杂种优势也取决于种群结构,但始终保持在较低水平,约为突变率或更低。将这些模式与由轻度有害突变引起的模式进行比较,以全面了解种群结构对近亲繁殖衰退、杂种优势和突变负荷的影响。