The absence of both kidneys associated with hereditary abnormalities in mice. ∗

Abstract

Recently the writer recorded the occurrence of fifty mice having in each case a solitary kidney. 1 They constituted 16 2/3 per cent of a group of 300 autopsied animals, descendants of animals that were subjected to light doses of x-ray irradiation. The treatment was apparently associated with the production of hereditary abnormalities of the eyes, feet and other parts of the body.

Several matings have now been made where in each case both parents had but one kidney, and the number of young per litter was considerably less than the average for animals with normal kidneys. Several of the young animals died during the first week of life and were promptly destroyed by their mother. The examination of a single litter of seven mice apparently throws considerable light on the high mortality shown in such animals and is considered of sufficient interest to warrant a brief report. In this instance, however, the male parent had but one kidney and was blind in the right eye, while the mother, although apparently normal, was heterozygous for such defects.

Two of the young of the above parents were found dead about 24 hours after birth. They had but recently died and at autopsy apparently showed complete absence of both kidneys. No other gross defects were noted except that one of the animals had a defective left eye. The remaining five animals were active and apparently in a good state of nutrition. Four of these were males with apparent'ly no external deformities, and one was a female with a defective left eye. Three of the animals were killed about 24 hours after birth, and the point of interest is that the female with the defective left eye showed bilateral absence of kidneys and one male had only a very small remnant of renal tissue on one side of the body.