A comparison of alternative distributions of postimplantation death in the dominant lethal assay

Statistical analysis of dominant lethal assay data has been the subject of much discussion, a large part of which has been concerned with the distributional form displayed by postimplantation embryonic deaths. The purpose of this study was to compare the fit of the frequently suggested distributions and some others, and to comment on the effect of distribution upon interpretation of results, using a particular set of dominant lethal assay data. The data set used included experiments involving a known mutagen (cyclophosphamide). For these experiments the parameters of the best fitting distributions were reviewed to consider how a dominant lethal effect is displayed.