ABSTRACT
The nude mutant affects the phenotype and main physiological parameters of the mouse already in utero, however, they do not lead in most individuals to a deep deterioration of the condition before the 4th month of life even in very “conventional” conditions, provided we do not infest them artificially with mouse hepatitis virus or toxoplasma. What proved to be the nude mutant was introduced by Isaacson and Cattanach in a report in Mouse News Letter in 1962. According to the first and timely monograph of J. Rygaard, Dr. N. R. Grist first saw the mutant, and one male without hair, a characteristic of the mutant, together with two phenotypically normal mice, male and female, were sent to the Institute of Animal Genetics in Edinburgh. Yet the nude mutation is due to one gene and it is likely that the gene affects some key protein factor which lies deep in the ontogeny of many, if not all, cellular and tissue systems.
