Telophase

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Telophase.svg

Telophase (from the Greek τέλος, "end" and φάσις, "stage"), is the final stage in both meiosis and mitosis in a eukaryotic cell.

During telophase, the effects of prophase and prometaphase (the nuclear membrane and nucleolus disintegrating) are reversed. Two daughter nuclei form in each daughter cell, and phosphatases de-phosphorylate the nuclear lamins at the ends of the cell, forming nuclear envelopes around each nucleus.[1] Two theories as to how this happens are:

  • Vesicle fusion—When fragments of the nuclear membrane fuse to rebuild the nuclear membrane
  • Reshaping of the endoplasmic reticulum—where the parts of the endoplasmic reticulum containing absorbed nuclear membrane envelop the nuclear space, reforming a closed membrane.[2]

As the nuclear membranes re-form around each set of chromatids, the nucleoli also reappear. The chromosomes also unwind back into the expanded chromatin that is present during interphase. Telophase accounts for approximately 2% of the cell cycle's duration. Chromosomes are uncoiled from spindle fibres and lengthened. Spindle fibres degenerate.

Reappearance of the nuclear membrane and nucleolus: the telophase

Cytokinesis usually occurs at the same time that the nuclear envelope is reforming, yet they are distinct processes.

In land plant cells, vesicles derived from the Golgi apparatus move to the middle of the cell along a microtubule scaffold called the phragmoplast. This structure directs packets of cell wall materials which coalesce into a disk-shaped structure called a cell plate. The cell plate grows out centrifugally and eventually develops into a proper cell wall, separating the two nuclei.

References[edit]

  1. ^ Molecular Cell Biology. 4th edition.. W H Freeman. 2000. pp. Section 13.4. 
  2. ^ Hetzer, Mertin (March 2, 2012). "The Nuclear Envelope". National Center for Biotechnology Information 2 (3): a000539. doi:10.1101/cshperspect.a000539. PMC 2829960. PMID 20300205. 

External links[edit]

  • Media related to Telophase at Wikimedia Commons