Table 4.

Identification of Drosophila transcription factors at different hybridization temperatures.

gene type	detected at 52°C	additionally at 51°C
transcription factors	32	47
other genes	2108	1623

The contingency table for the numbers of Drosophila transcription factors and other genes identified as differentially expressed at optimal and suboptimal hybridization temperatures shows that transcription factors were strongly overrepresented amongst genes only detected at the optimal hybridization temperature of 51°C (Fisher's exact test p < 0.01).