Designing in vitro tools to pattern gene expression using inducible gene expression

Abstract

Early embryogenesis involves the sequential patterning of gene expression in different regions of the developing embryo, with the ultimate purpose of guiding initially identical cells into different paths of differentiation and thus facilitating body part formation and patterning. Being able to reproduce patterns of gene expression that lead to formation of a specific tissue in vitro would be useful both for engineering artificial tissues, and for developing simplified in vitro models to study and define the rules that guide tissue morphogenesis. Here we report a system to pattern gene expression in epithelial sheets using a drug inducible gene expression system. We created a sheet of epithelial cells transduced with a doxycycline inducible lentivirus encoding GFP. We then delivered patterns of doxycycline to the cell sheet to create controlled patterns of GFP expression. We show that the stability of the gene expression patterns in vitro heavily depends on the relationship between the dynamics of the inducible gene expression system and the dynamics of cellular rearrangements. By modeling the system we can predict the conditions that allow stable gene pattern formation.