摘要
作者从数学上导出了基因作图的三点自交方法。这一方法同三点测交法一样能提供各种作图信息，但不需要选育三隐性纯合基因亲本或品系，因而能大大提高作图功效。从理论上证明，该方法也适合于小群体作图分子标记连锁图谱。同时用Ｒｓｈｅｒ单一观察信息（即Ｆ信息）量证明，三点自交法是一种有效的作图方法。应用 ＭＡＰＭＡＫＥＲ程序中所提供的老鼠 Ｆ２群体中３３３个个体的１２个ＲＦＬＰ标记位点中前６个位点的数据对三点自交法的作图功能进行了检测。结果表明，三点自交法在位点间的连锁关系检测，连锁群中位点的排序和图距计算具有与ＭＡＰＭＡＫＥＲ程序一样的功能，而且还提供了位点间的交叉干涉和位点的相引或相斥构型等信息以及紧密位点间发生负干涉作用的证据。
The method for constructing linkage maps has almost been so far the three-point testcross in higher organisms. This method is, however, considerably limited to a requirement of a parent or line with three recessive genes that can be obtained by only cross breeding. In this paper, the three-point self cross method for mapping was proposed. This method can also provide us with informations of mapping as the same as the three-point testcross method. However, the three-point selfcross method does not have any limitation of requring a parent with three recessive genes. It was theoretically proved that this method could be used to map molecular marker loci in small sample of Fi population. Exactly to test both the methods for mapping, Fisher information content was applied to prove that the three-point self cross method is powerful for mapping. Further to test mis method, data of the first 6 loci were chosen from 12 RFLP loci detected in 333 F2 individuals in SAMPLE. RAW file in MAPMAKER/ EXP version 3.0 that Lander et al. (1987) provided. The result showed that, like MAPMAKER program, the three-point self cross method is Powerful to detect linkage relationship among loci, to order them on linkage groups and to calculate distances between nearest neighbor loci. Besides, this method could provide us with the other information of map such as the positive or negative interference and couple or repulsion configuration.
基金
国家自然科学基金(39870568)
