Asexual Cells Research Articles

Anthracobia, Ascodesmis, Pyronema, and Trichophaea in Culture

SUMMARYBrief descriptions of apothecia, asexual states present, and cultural characteristics of operculate Discomycetes, Anthracobia muelleri, Ascodesmis sphaerospora, Pyronema domesticum, and Trichophaea abundans, on various agar media are provided. Rabbit food agar is an excellent medium for obtaining apothecia of these species. Formation of apothecia and the Rhizoclonia-like asexual cells of Anthracobia muelleri in culture is reported for the first time. Lasiobolus equinus, Trichophaea hemisphaeroides, and Trichophaea sp. ATCC 14016 did not form apothecia or any asexual state.

Nuclear division without cytokinesis followed by fusion of pronuclei in Paranotila lata gen. et sp. nov.

SYNOPSIS. Under the influence of ecdysone a uninucleate asexual cell of Paranotila lata gen. et sp. nov. is transformed into a gametocyte in which, as a rule, 8 successive nuclear divisions occur, thus producing 8 male and 8 female pronuclei. No cytokinesis occurs during these divisions. The process should be regarded as a gametogenesis in which only nuclei participate. These gametic pronuclei fuse, male with female, and produce 8 fusion or zygotic nuclei. The cell may now be regarded as a zygote, which soon undergoes plasmotomy, and eventually produces 8 uninucleate, diploid asexual cells. This is the usual course of events. A few exceptions or irregularities have been noted. Throughout gametogenesis, Paranotila is quite indifferent regarding the production of new flagella and axostyles; sometimes they are produced, sometimes they are not.