应用贝叶斯理论推断DNA分子标记基因型

Inferring Genotype of DNA Molecular Marker by Bayesian Theorem

引入贝叶斯理论用以从ＤＮＡ分子标记的表现型（电泳谱带）推断其基因型（ＤＮＡ来源）。结果表明，根据标记座位独立假定而确定的遗传信息不完全标记的基因型概率，与根据邻近的遗传信息完全标记的基因型和有关重组率算得的相应贝叶斯概率，通常都有很大的差异。所以在进行数量性状基因定位和标记辅助选择等工作之前，应当计算每一个体基因组上所有遗传信息不完全座位的有关基因型的贝叶斯概率。文中列出计算未知基因型的贝叶斯概率的详细过程，也讨论了贝叶斯概率的若干推广应用。

Bayesian theorem is applied to infer DNA molecular marker genotype (DNA chain type) from its phenotype (electrophoresis band type). The results indicate that large difference often presents in the genotype probability of a molecular marker with incomplete genetic information when it is obtained from the assumption of independence among markers as compared with that inferred from the genotypes of the flanking markers with the complete genetic information and the recombination fractions among them based on the Bayesian theorem. Therefore, before utilizing the marker information, such as in mapping quantitative trait loci (QTL), marker assisted selection (MAS) etc., Bayes' probability of the genotype for all markers with incomplete genetic information must be calculated over the whole genome for every individual. This study provided detailed procedure for the calculation of the Bayes' probability of the unknown DNA genotype. Several extensions were also discussed for the application of the Bayesian theorem in genetics.