Statistical tests for recessive lethal-carriers

This paper presents a statistical method for testing whether a male mouse is a recessive lethal-carrier. The analysis is based on a back-cross experiment in which the male mouse is mated with some of his daughters. The numbers of total implantations and intrauterine deaths in each litter are recorded. It is assumed that, conditional on the number of total implantations, the number of intrauterine deaths follows a binomial distribution. Using computer-simulated experimentation it is shown that the proposed statistical method, which is sensitive to the pattern of intrauterine death rates, is more powerful than a test based only on the total number of implant deaths. The proposed test requires relatively simple calculations and can be used for a wide range of values of total implantations and background implant mortality rates. For computer-simulated experiments, there was no practical difference between the empirical error rate and the nominal error rate.