Proliferation and growth of intestinal epithelium in Ascaris suum (Nematoda) during postnatal ontogeny. Communication III. Mitotic anomalies and changes in ploidy and nucleus size.

Abstract

It was established by cytophotometry that the amount of DNA in intestinal-epithelium cells rises from the diploid to a tetraploid level during the early postnatal ontogeny of ascarids so that eventually nuclei with a diploid quantity of DNA practically disappear. Apart from this, there appear cells with a higher DNA content: 8c, 16c, 32c, and even 64c. Pictures of anomalous mitotic processes, as well as polypoid meta- and anaphases, were also observed. A result of the polyploidization is an increased size of nuclei and cells, but nucleus size is not always correlated with the DNA content. The previously established sixfold increase in the mean volume of intestinal cells during postnatal ontogeny of the ascarid is due to their transition to the new ploidy level and additional "paragenomic" growth of the polypoid cells.