A new meiotic abnormality in Zea mays: multiple spindles associated with abnormal cytokinesis in both divisions.
Abstract: We report here a new meiotic abnormality recorded in one plant of an inbred line of Zea mays. After an apparently normal prophase I, chromosomes did not congregate in a single metaphase plate. Bivalents remained scattered in the cytoplasm, giving rise to several spindles. Despite the occurrence of multiple spindles, meiosis I proceeded normally, forming a varied number of nuclei at telophase I. The presence of one or a few chromosomes in the nucleus was enough to induce local cytokinesis, which was evident from metaphase I. Each cell resulting from meiosis I expressed its own program and progressed through the cell cycle. Therefore, failure of chromosome congregation on a single plate also occurred at meiosis II, where further irregular cytokinesis was observed. As a consequence of the two abnormalities, polyads occurred, resulting in pollen grains of different sizes and in sterility at a frequency of up to 93.5%.
Caetano-Pereira
C M
CM
Centro Federal de Eduçacão Tecnologica de Paraná (CEFET-PR), Brazil.
Pagliarini
M S
MS
D001938:Brazil; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D020732:Cytogenetic Analysis; D008540:Meiosis / Q000235:genetics*; D008677:Metaphase / Q000235:genetics / Q000502:physiology; D009154:Mutation; D008941:Spindle Apparatus / Q000235:genetics*; D003313:Zea mays / Q000166:cytology / Q000235:genetics*