Table 2. Ten identified midline and tracheal enhancers.
| Gene | Size1 | Position2 | Tissue | Midline cells3 | Tracheal cells4 |
| CG33275 | 753 | exon 5+ intron 5 | midline | glia (st. 13) | – |
| 1297/265 | intron 5 | trachea | – | all (st. 11)/fusion cells (st. 13) | |
| esg | 3092 | ∼ 5 kb downstream | midline | glia, MNB and progeny (st.12) | – |
| 3586 | downstream | trachea | – | larval fusion cells (1st instar) | |
| 3468 | ∼ 20 kb downstream | trachea | – | larval fusion cells; secondary branches (1st instar) | |
| liprin γ | 889/182 | intron 1 | both | glia (st. 12)/glia and sporadic in MNB and progeny (st. 12) | DT(st. 15)/all (st. 13) |
| Net | 797 | ∼ 10 kb downstream | both | mostly glia (st. 12) | all but DT (st. 12) |
| comm | 443 | 3′ untranslatedregion | both | all midline cells (st. 10) | larval dorsal trunk and some secondary branches (st. 17) |
| moody | 1221 | intron 1 | trachea | – | posterior DT (st. 15) |
| Ect3 | 517 | upstream of Ect3/intron 1 of Tk | midline | glia, MP1s, H cell and H cell sib (st. 10) | – |
1 The size of the minimal fragment with enhancer activity,
2 the position of the enhancer relative to the gene and 3midline and 4tracheal cells that exhibit enhancer activity are indicated.
3,4 The stage of development when reporter expression is first observed is indicated in parentheses. The absence of expression in the midline or trachea is indicated with a dash.