Mechanical Properties of Xenopus Egg Cytoplasmic Extracts
Original Entry: Peter Foster, AP 225, Fall 2011 In Progress...
Authors: M. T. Valentine, Z. E. Perlman, T. J. Mitchison, and D. A. Weitz
Publication:Perlman et al. Mechanical properties of Xenopus egg cytoplasmic extracts. Biophysical journal (2005)
This paper deals with the mechanical properties of cytoplasmic extracts from Xenopus laevis (African tree from). Xenopus extract is a common system because it's relatively easy to crush the eggs and extract the cytoplasm and each egg contains everything needed for ~30 divisions. Because of how well used this system is, it's interesting to consider the mechanical properties. This egg extract is used as an example system to try to study cytoplasm mechanics in general. In the paper, conventional macroscopic rheological measurements are made as well as microscopic microrheological measurements.
Figure 1 shows results for the time evolution of the elastic moduli (top panel) and the viscous moduli (lower panel) obtained using a conventional strain controlled rheometer. Each of the curves shown represents a separate measurement and it is evident that there is substantial variation. The common theme between all of the runs is that the extract forms a gel that acts like a soft solid (G/G' ~ 0.3-0.5)
Perlman et al. Mechanical properties of Xenopus egg cytoplasmic extracts. Biophysical journal (2005))