Hereditary visceral abnormalities in the descendants of irradiated mice.

Abstract

About a year ago 1 , 2 , 3 , 4 the writer mentioned the occurrence of several mice with kidney defects that were descendants in the sixth and subsequent generations of certain x-rayed animals in which an attempt had been made to alter the germ plasm by physical agents. For details concerning the work leading to these studies, and the data so far recorded, the reader is referred to the references given below.

The present communication deals with the results of 1817 autopsies of the descendants of mice with visceral abnormalities, which are mainly of the urinary system but are also associated with other visceral disturbances. Preliminary genetic results are also given to show the nature of the inheritance of these abnormalities. The following is a brief summary of the types of visceral abnormalities so far observed with the number of individuals in each group recorded in parenthesis:

A. In adult animals: 1. Kidneys moderately unequal in size, with no hypertrophy of the larger (5). 2. One kidney nearly completely missing and hypertrophy of the other (3). 3. One kidney normal and the other pathological; polycystic kidneys (3), hydronephrotic kidneys (3). 4. Kidneys in reversed position, situs ittversus visceruwz (1). 5. Absence of one kidney (285). The solitary kidney is usually, but apparently not always, hypertrophied.

B. In 1142 animals examined within a few hours of birth : 1. Kidneys unequal in size (8) 2. Congenital absence of one kidney (132). No hypertrophy of the solitary kidney was noted within 24 hours of birth. 3. Congenital absence of one kidney and reduction in size of the other (11). 4. Congenital hydronephrosis (9). In five instances the hydronephrotic kidney was solitary, while in 4 an apparently normal kidney was the mate of the abnormal one. A tortuous and much distended ureter is associated with this condition. 5. Congenital absence of both kidneys (149). The adrenal glands are apparently normal. The animals are born alive, of apparently normal size and activity, and live for about 24 hours.

Localized fetal hemorrhages of the viscera have been noted associated with kidney abnormalities in the following locations : region of the kidneys (3);liver (7); testis (9), there was one animal with a missing testis; pancreas (1).