Details

Autor(en) / Beteiligte

• Underbrink, A. G.
• Sparrow, A. H.
• Rogers, Anne F.
• Pond, Virginia

Titel

Observations on the Cytology and Fine Structure of Mitosis in the Fern, Ophioglossum petiolatum Hook

Ist Teil von

• CYTOLOGIA, 1967/12/30, Vol.32(3-4), pp.489-499

Ort / Verlag

Tokyo: Japan Mendel Society, International Society of Cytology

Erscheinungsjahr

1967

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Persisting nucleoli were found in the fern, Ophioglossum petiolatum Hook. The nucleoli remain attached to the chromosomes until meta-anaphase at which time they are extruded from the spindle and are displaced poleward to become situated in the peripheral cytoplasm. They may persist through interphase and into the next mitosis. The nucleoli undergo structural changes during mitosis. They apparently lose the dense granular components present in interphase nucleoli and appear as loosely organized fibrous masses. A tripolar spindle was observed in which the spindle appeared to be slightly twisted. The high chromosome number (2n≈1020) facilitated the study of the centromere region, although no fine structural differentiation of this structure was found. Spindle fibers do not converge on highly localized poles but tend to become disorganized in the polar regions. The presence of undulations and sinuses along the length of the chromosomes suggests. coiling of the chromosomes and a subchromatid structure.