Studying the Effect of Adhesion Area on the Thickness of Cortical Actin

Duttagupta, Madhura (2016) Studying the Effect of Adhesion Area on the Thickness of Cortical Actin. Masters thesis, Indian Institute of Science Education and Research Kolkata.

PDF (MS dissertation of Madhura Duttagupta (11MS082)) Madhura_11MS082_MSThesis.pdf - Submitted Version Restricted to Repository staff only Download (1MB)

Abstract

Cell rounding is known to be an essential pre-requisite for mitosis. We know that loss of adhesion permits cell rounding. The actomyosin cortex is necessary for maintaining the rounding force against adhesion. It is suggested that, as cells enter mitosis, loss of adhesion permits cell rounding. Understanding the cortex necessitates knowledge of the mechanics and dynamics of the cortical actin together with its geometrical arrangement. We have two major aims: Firstly, to determine whether there is any dependence of cortical actin thickness on adhesion area in non-mitotic cells. We obtained adherent eukaryotic cells on micropatterns of different shapes and sizes and estimated their adhesion areas as well as cortical thicknesses. We found that smaller adhesion area leads to a thicker cortex, however this dependence did not hold beyond 450μm². Next, we wanted to determine what happens to this dependence of cortical thickness on adhesion area, when the cell is allowed to choose its adhesion area. We created a pattern where adhesion is controlled in only one axis, leaving the cell to choose the extent of adhesion in the other and determined the preferred cortical actin thickness. We found that, given a choice, the cell chooses a smaller adhesion area, which is less than in the case of uncontrolled adhesion, while the cortical actin thickness has been lowered to a saturating value. Our results indicate that the choice of adhesion area influences the cortical thickness to an extent. We need to obtain cells having intermediate adhesion areas to further cement our claim.

Actions (login required)

View Item