Fluorescent (F) bodies in the spermatozoa of man and the great apes

Abstract
Mature spermatozoa of the chimpanzee (Pan troglodytes), the gorilla (Gorilla gorilla), and the orangutan (Pongo pygmaeus) were stained with quinacrine dihydrochloride. Fluorescent (F) bodies were visualized in the spermatozoa of the chimpanzee and gorilla but were absent in the orangutan, in which there is no brilliant fluorescence in any chromosome. The F bodies appeared to be randomly located in the sperm heads of these two species, as they usually are in human spermatozoa. However, the proportion of sperm showing one or more F bodies in the chimpanzee and gorilla was not comparable to what is usually found in man. The F bodies in the chimpanzee presumably represent brilliant regions in the autosomes, since the Y chromosome has no brilliant fluorescence in this species. This is contrary to man, in which the F body is an useful indicator of the Y chromosome. In the gorilla, the F bodies probably correspond to both the Y chromosome and to some brilliant regions in the autosomes.