Refractile bodies in the developing and mature spermatozoa of Childia groenlandica (turbellaria: Acoela) and their possible significance.

Abstract

1. Living and fixed mature spermatozoa of Childia groenlandica (Turbellaria: Acoela) have conspicuous refractile bodies present behind the oval nucleus, in a double longitudinal row in the tail; an undulating membrane is also evident, as well as (in some cases) a slender head filament which is not a flagellum but which may be the result of an acrosome reaction. The living spermatozoa are 50-60 microns long and moderately motile. In living and fixed specimens, the refractile bodies are found at least as early as the secondary spermatocyte stage and increase in numbers rapidly during the spermatid stages.2. The following results were obtained with cytochemical tests of the refractile bodies: (a) Feulgen, for DNA, negative; (b) methyl green-pyronin and azure B, for RNA, positive before and after RNase and PCA extraction; (c) alcian blue/ PAS for polysaccharides, positive before and after diastase digestion, for small accumulations of acid mucopolysaccharide (s) in centers, only, of refractile bodies; (d) Sud...