Genetic control of liability to infection withNematospiroides dubiusin mice: selection of refractory and liable populations of mice

Abstract

SUMMARYQuackenbush strain and wildMus musculuswere assayed for their liability to primary infection with 100 LaNematospiroides dubiususing an experimentally derived selection index. Refractory and liable colonies of mice were established over 5 generations. Liability toN. dubiusinfection was found likely to be controlled by several genes; the heritability (h2) of this trait was estimated at 0·45. Positive linear correlation was found between the number of parasite eggs voided and the number of adultN. dubiusrecovered, negative correlation between the pre-patent period of infection in days and the number of parasite eggs voided and positive correlation in 2 of 5 generations between live mouse body weight and the number of adultN. dubiusrecovered. Further, positive correlation was found between the liability of female mice toN. dubiusand their progeny litter size number. The genetic mechanisms controlling the liability trait and the possible evolutionary significance of these results are discussed.