Where the asymmetry in gene expression starts

Imrich Barák

Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava 45, Slovakia; phone: ++421 2 5930 7418, fax: ++421 2 5930 7416, e-mail: imrich.barak@savba.sk

A general problem in developmental biology is the process by which cells of one type give rise to two dissimilar daughter cells. Although, these two daughter cells are genetically identical and contain identical chromosomes they differ from each other morphologically, physiologically and also they can have a different fate. Bacillus subtilis sporulation represents an excellent model to study one of the simplest differentiation process in great detail. Many interesting questions have been raised in the course of studies of this relatively simple cell differentiation process. Firstly, how does the cell decide when to sporulate and what are the signals? Secondly, what is the mechanism by which morphological asymmetry arises and how is the sporulation septum formed? Thirdly, how is the hierarchical regulatory cascade of sigma factors switched on and how are changes in gene expression coordinated with changes in cell morphology? Several decades of study of this process have provided insight into cell cycle regulation and development. Important advances were achieved in our understanding of asymmetric gene expression during spore formation. The work in our laboratory is emphasized on development stages that lead to asymmetric septum formation and especially to activation of the first compartment specific sigma factor - s^F.

Acknowledgements

Work in author’s laboratory is supported by grant 2/1004/22 from the Slovak Academy of Sciences and Wellcome Trust Project and Collaborative Research Initiative Grants 066732/Z/01/Z.