GENETIC AND PHYSIOLOGICAL STUDIES OF BLOOD PRESSURE IN MICE. I. CROSSES BETWEEN A/J, SWR/J, AND THEIR HYBRIDS

Abstract

Analysis of data from crosses between the A/J and SWR/J strains showed that the genic action of the alleles affecting blood pressure by which these strains differ act additively in the males. The apparent partial dominance observed in the female data was due to the truncation of the upper tail of the distribution of blood pressures in the SWR/J strain. When the data were corrected for this truncation, an additive model of inheritance also fitted the female data.The genetic control of hematocrit per cent and relative kidney weight was indicated. The inheritance is additive for hematocrit, and is more complex for relative kidney weight where epistatic interactions are involved. The A/J and SWR/J strains did not differ in renin granularity.The interrelationship of hematocrit per cent, relative kidney weight, renin granularity, and blood pressure was investigated. Hematocrit and renin granularity were considered not to be the source of the blood pressure differences between the two strains. Significant phenotypic and genetic correlations between relative kidney weight and blood pressure were discernible in the male data, but not among the females.