Model for Ttk69 regulation of lz in Drosophila eye development. Model for the regulation of lz based upon data from this study, Behan and colleagues [39,41] and Yan and colleagues . In undifferentiated cells, So and Gl initiate the expression of lz (red oval represents Lz protein product). Yan and Ttk69, both transcriptional repressors, are required to down-regulate expression of lz in undifferentiated cells, keeping Lz levels at an appropriate level. Upon activation of the Ras1/MapK signal transduction cascade, the repressive effects of Yan and Ttk69 on lz expression are relieved, thus enabling cell fate specification events in the R7 cell to proceed.
Siddall et al. BMC Developmental Biology 2009 9:64 doi:10.1186/1471-213X-9-64