Cleavage furrow site determination in cytokinesis

Abstract

Cytokinesis is the final step in cell duplication, physically dividing the cell into two daughter cells. During cytokinesis a cleavage furrow is formed and ingresses between the two future daughter cells. Bringmann & Hyman (2005) recently found that, in C. elegans, two consecutive signals from midzone and astral microtubules are responsible for correct positioning of the cleavage furrow. In this thesis is discussed which microtubules are responsible for this signalling in mammalian systems and how these microtubules induce formation of the cleavage furrow. Different experiments will be described, first in different model organisms and then in mammalian systems, which tried to elucidate which microtubules are important for cleavage furrow site determination and assembly. Microtubules alone can not form a cleavage furrow, but are thought to direct molecular signals to the right position in the cell so they can induce formation and contraction of the cleavage furrow as well as also locating other molecular signals. What is known about the different molecular signals and their function will be discussed in the final chapter