Within-generation mutation variance for litter size in inbred mice
Within-generation mutation variance for litter size in inbred mice
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DOI：
10.1534/genetics.108.088070
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发表时间：
2008-08-01
期刊：
影响因子：
3.3
通讯作者：
Medrano, Juan R.
中科院分区：
文献类型：
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作者：
Casellas, Joaquim;Medrano, Juan R.
每代遗传变异的突变输入(sigma（2)(m)）是小鼠近交系遗传变异的下限，尽管由于新突变在连续几代的积累，可能会有更大的值。采用贝叶斯方法对C57BL/6J自交系46代的sigma(2)(m)和产仔数的累积遗传变异进行了分析。这允许对sigma(2)(m)和基础群体中的加性遗传方差(sigma（2)(a)）进行单独的推断。基代的加性遗传方差为0.151，在第10代迅速降低到几乎为零。另一方面，σ (2)(m)为中等（0.035），代内突变方差增加到第14代，其余世代在0.102 ~ 0.234之间振荡。这一模式表明在产仔数上存在连续的遗传变异上传（h(2) = 0.045）。在该人群中未发现相关的遗传漂变。总之，我们的方法允许在混合模型框架内单独估计sigma(2)(a)和sigma(2)(m)，并且获得的遗传力突出了新的遗传变异对自交系遗传稳定性的显著和持续影响。
The mutational input of genetic variance per generation (sigma(2)(m)) is the lower limit of the genetic variability in inbred strains of mice, although greater values could be expected due to the accumulation of new mutations in successive generations. A mixed-model analysis using Bayesian methods was applied to estimate sigma(2)(m) and the across-generation accumulated genetic variability on litter size in 46 generations of a C57BL/6J inbred strain. This allowed for a separate inference on sigma(2)(m) and on the additive genetic variance in the base population (sigma(2)(a)). The additive genetic variance in the base generation was 0.151 and quickly decreased to almost null estimates in generation 10. On the other hand, sigma(2)(m) was moderate (0.035) and the within-generation mutational variance increased up to generation 14, then oscillating between 0.102 and 0.234 in remaining generations. This pattern suggested the existence of a continuous uploading of genetic variability for litter size (h(2) = 0.045). Relevant genetic drift was not detected in this population. In conclusion, our approach allowed for separate estimation of sigma(2)(a) and sigma(2)(m) within the mixed-model framework, and the heritability obtained highlighted the significant and continuous influence of new genetic variability affecting the genetic stability of inbred strains.