# Paris\Modelling Variables

### From 2007.igem.org

**After analysis the design of the different parts and the interaction between them, we define 4 variable of interest and one optional **

## Contents |

## Number of soma cells (S)

The S (soma cells) are the cells which provide the DAP to the germe cell, so the size of this kind of cells is a very important factor to prevent the system to collapse.

They are issue from the differentiation of the germe cells. So the *production* of S depends on the number of germe cells, and on the concentration of CRE.

Like all the others cells, S may die, for the moment we think about a linear coefficient to represent the death of the cells.

## Number of germe cells (G)

The G (germe cells) are DAP-auxotrophe cells, they can divide or differentiate. More G they are, more DAP is needed, so they depends on S.

G can divide so the shape of the curve of G augmentation is the same as other growth rate evolution.

G can die too, (like for S a linear coefficient), and it can differentiate.

## Concentration of CRE

The system loxp::CRE will make enable the differention between G and S Cells by removing a device which is needed for division and for metabolic dependence So CRE is a important actor.

## Concentration of DAP in the medium

The CRE production will be under the control of DAP

DAP will diffuse in the medium

## Concentration of DAP in the cells

DAP in the cell will inhibate the differentiation process