The nuclear DNA and RNA distribution in Pelomyxa spp. (Amoebozoa, Archamoebae, Pelobiontida) revealed by a simple-to-use DAPI/pyronin staining method.

The genus Pelomyxa includes 15 species of anaerobic Archamoebae with remarkable diverse nucleoplasm morphology. Nuclear structures, like chromatin and nucleoli, of several members of the genus was previously identified only based on their ultrastructural similarity to typical structures of somatic cells of higher eukaryotes. Here, we explored an easy-to-use, one-step intravital staining method with DAPI and pyronin to distinguish between DNA and RNA structures in nuclei of unfixed cells of Pelomyxa belevskii and P. stagnalis significantly varying by nuclear organization. Our method can be used for rapid diagnosis of DNA and RNA-containing structures in species with complex nuclear organization.