Figure 1

Number of features above background. RNA from 15 olfactory epithelia (eight rats were killed, but one olfactory RNA sample did not pass the quality control test (the RIN test) and was not further processed) were hybridized in parallel. The y-axis represents the number of transcripts plotted against the number of samples (0 to 15) with a hybridization signal above background levels, as defined by GeneSpring. Transcripts for which 11 or more of the 15 samples (73%) gave raw values above background levels were scored as "expressed". Transcripts positive in 1 to 10 samples were scored as "weakly expressed". All other transcripts were scored as "not expressed".