Figure 4. Real-time quantitative PCR gene expression analysis for control (left eyes, white bars) and injured retinas (right eyes, black bars). For each graph, the levels of gene expression for nestin (A), synemin (B), glial fibrillary acidic protein (GFAP; C), and vimentin (D) were normalized relative to the geometric mean of the four housekeeping genes: glyceraldehyde phosphate dehydrogenase, glucose phosphate isomerase, TATA box binding protein, and ubiquitin C. In general, mRNA levels were elevated at all injury time points. The p value shown for the average data was computed using a paired two-tailed Student t test (n=3). In this study, values of 0.01 or higher were considered statistically significant. Error bars denote standard deviations (SD).