Chakravarti A, Slaugenhaupt S A
Department of Biostatistics, University of Pittsburgh, Pennsylvania 15261.
Genomics. 1987 Sep;1(1):35-42. doi: 10.1016/0888-7543(87)90102-9.
A lod score method is provided for mapping genes relative to the centromere using family data from autosomal trisomies. Such gene-centromere mapping can be performed whenever two or more members of a meiotic tetrad can be recovered. The critical mapping parameter is not the recombination value theta or the map distance omega, but the probability of nonreduction in a heterozygous host, the probability of heterozygosity (nonreduction) is 1-gamma/2 for a meiosis I error and gamma for a meiosis II error. Under various assumptions regarding chiasma interference, gamma can be related to theta and omega. We provide specific methods for estimating gamma and theta from trisomy data using maximum likelihood, so that recombination may be studied on chromosomes that underwent nondisjunction.
提供了一种对数优势计分法，用于利用常染色体三体的家系数据来绘制相对于着丝粒的基因图谱。只要能回收减数分裂四分体的两个或更多成员，就可以进行这种基因-着丝粒图谱绘制。关键的图谱参数不是重组值θ或图距ω，而是杂合宿主中不发生减数分裂的概率，对于减数分裂I错误，杂合性（不发生减数分裂）的概率为1-γ/2，对于减数分裂II错误，概率为γ。在关于交叉干涉的各种假设下，γ可以与θ和ω相关。我们提供了使用最大似然法从三体数据估计γ和θ的具体方法，以便能够研究发生了不分离的染色体上的重组情况。
