A new model for nuclear envelope breakdown

Mol Biol Cell. 2001 Feb;12(2):503-10. doi: 10.1091/mbc.12.2.503.


Nuclear envelope breakdown was investigated during meiotic maturation of starfish oocytes. Fluorescent 70-kDa dextran entry, as monitored by confocal microscopy, consists of two phases, a slow uniform increase and then a massive wave. From quantitative analysis of the first phase of dextran entry, and from imaging of green fluorescent protein chimeras, we conclude that nuclear pore disassembly begins several minutes before nuclear envelope breakdown. The best fit for the second phase of entry is with a spreading disruption of the membrane permeability barrier determined by three-dimensional computer simulations of diffusion. We propose a new model for the mechanism of nuclear envelope breakdown in which disassembly of the nuclear pores leads to a fenestration of the nuclear envelope double membrane.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenine / analogs & derivatives*
  • Adenine / pharmacology
  • Animals
  • Cell Membrane / metabolism
  • Dextrans / metabolism
  • Female
  • Microinjections
  • Models, Biological
  • Nuclear Envelope / metabolism*
  • Nuclear Envelope / ultrastructure*
  • Oocytes / cytology
  • Oocytes / metabolism
  • Oocytes / ultrastructure
  • RNA, Messenger
  • Starfish


  • Dextrans
  • RNA, Messenger
  • 1-methyladenine
  • Adenine