植物三种不同遗传方式基因的地理家系谱理论与应用初探(英)  

A Preliminary Approach to the Theory of Geographical Gene Genealogy for Plant Genomes with Three Different Modes of Inheritance and Its Application

作　　者：胡新生[1] 

机构地区：[1]中国林业科学研究院林业所,北京100091

出　　处：《Acta Genetica Sinica》2000年第5期440-448,共9页

摘　　要：将已知用于从地理空间上离散或连续分布群体随机抽取基因样本的基因家系谱理 论推广到两性异交植物上。由于存在不同的群体间基因迁移率，对３种不同遗传方式的植物 基因组（核、叶绿体和线粒体ＤＮＡ）分别进行了研究。理论上证明对于不同遗传方式的基因， 通过相应适当调整有效群体大小和迁移率，现有的基因家系谱理论可直接应用于植物群体 上。其中一个结论就是当从离散分布群体中随机抽取ｎ个基因样本时，亚群体间的花粉流和 种子流的相对比率可以用亚群体间和亚群体内的ＤＮＡ碱基序列总差异数量估计值来估算。 另一具有理论意义的结论是在离散分布的群体结构模型中，父本遗传的单倍体基因（针叶树 的叶绿体ＤＮＡ上的基因）的平均同祖并合发生时间最短，而在一定条件下，母本遗传的单倍 体基因（被子植物的叶绿体ＤＮＡ和被子或裸子植物的线粒体ＤＮＡ上的基因）的平均同祖并 合发生时间最长，然而这两个结论在连续分布的群体遗传结构模型却难以获得。This paper extends to hermaphrodite outcrossing plant populations the existing gene genealogy theories for a sample of genes randomly chosen from geographically discrete or continuously distributed populations. Three plant genomes (nuclear, chloroplast and mitochondrial DNA) with different modes of inheritance are considered separately due to the difference in migration rates. It is shown that on certain assumptions, the previous coalescence theories can be applied to plant by appropriate reparametrization of the effective population size and migration rate specific to each genome. One result is that estimation of the ratio of pollen to seed flow from a sample of n (n≥2) individual genes can be obtained in terms of the number of segregating sites between and within populations that are discretely distributed in space. Another result of theoretical interest is that in the discrete model of population structure, mean coalescent time is the shodest for the paternally inherited genes (cpDNA in conifers) and, given certain conditions, is the longest for the maternally inherited genes (cpDNA in angiosperms and mtDNA in conifers and angiosperms). However, these results are difficult to obtain in the model of population that is continuously distributed in space.

关 键 词：基因家系谱 植物地理 父本遗传 母本遗传 

分 类 号：Q943[生物学—植物学]