Abstract
Purpose: :
The eye develops from the most anterior part of the neural plate in a region known as the eye field. Seven eye field transcription factors (EFTFs) are coordinately expressed in the eye field at the time of its specification and each is required for normal eye formation. We recently discovered that coordinated expression of the EFTFs is sufficient to divert pluripotent cells from a skin to eye field-like fate. The purpose of this work was to identify EFTF-targets regulated during eye formation.
Methods: :
We used microarray analysis to compare the transcriptional profile of EFTF expressing pluripotent cells with that of the endogenous eye field. Quantitative RT-PCR (qRT-PCR) and whole mount in situ hybridization (WISH) was then used to validate the microarray results.
Results: :
We identified 181 EFTF-induced genes that were also enriched in the eye field (1.4-fold). Fifty-one genes were repressed by the EFTFs and depleted in the endogenous eye field. Of 49 genes (35 induced; 14 repressed) selected for validation by qRT-PCR (~21% of the total), 46 (35 induced; 11 repressed) or ~94% were appropriately regulated by the EFTFs. WISH confirmed that four unannotated yet highly conserved Eye Primordia Genes (EPGs 29, 140, 147 and 185) were expressed in the eye field.
Conclusions: :
We have identified 232 genes that appear to be regulated by the eye field transcription factors. The high rate of qRT-PCR validation suggests our screen was robust, and the majority of these genes are either direct or indirect EFTF targets. Many of the identified genes were unannotated. Future work will focus on the functional characterization of novel genes, such as EPG 29, 140, 147, and 185 and their potential role in early eye formation.
Keywords: retinal development • gene microarray • gene/expression