Figure 8. A list of genes associated with retinal ganglion cells. Rows 1, 3, and 18 list three ganglion cell signature genes used as bait with which to trap new candidate genes. How to generate a synthetic trait from three or more transcripts: Step 1. Select a set of transcripts or other traits (even classic phenotype will work) and add them to the Trait Collection as described in the legend to Figure 6, steps 1 and 2. For example, add the transcripts for Thy1, Nrn1, and Gap43 (probe sets 1423135_at, 1428393_at, 1423537_at). Step 2. Select the check boxes of the probe sets in the Trait Collection window and then click the 'Correlation Matrix' button. A new window will open. Scroll down to the section labeled PCA Traits. One or more synthetic traits will be listed here. PC01 is the synthetic trait that shares the most in common with the set of traits that you submitted for analysis. Step 3. Click on the blue text of PCA Trait PC01. This will open a Trait Data and Analysis page that can now be used for various functions, including mapping and correlation analysis. Step 4: To find other transcripts that share features with the PC01 trait constructed using Thy1, Nrn1, and Gap43, scroll to the 'Traits Correlations' section of the Trait Data and Analysis page. Before clicking the Trait Correlation button change the Choose Database pull-down menu to read Eye M430v2 (Sep08) RMA data.