Table 2.
The genes modulated by dietary salt are predominantly expressed in tubule and hindgut
| Treatment |
Number of Genes With Maximal Expression in Tissue |
Total | χ2 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Brain | Head | Crop | Midgut | Tubule | Hindgut | Ovary | Testis | Acc | l_fat | tag | car | Fly | |||
| All FlyAtlas | 1,783 | 463 | 1,134 | 1,324 | 791 | 571 | 2,563 | 2,655 | 2,386 | 1,518 | 900 | 1,856 | 144 | 18,088 | |
| 4 h up | 0 | 0 | 0 | 2 | 25 | 22 | 0 | 0 | 1 | 0 | 5 | 7 | 2 | 64 | 426 |
| 8 h up | 0 | 0 | 0 | 2 | 25 | 22 | 0 | 0 | 1 | 0 | 4 | 7 | 2 | 63 | 432 |
| 16 h up | 0 | 2 | 1 | 10 | 33 | 40 | 5 | 0 | 2 | 0 | 16 | 26 | 0 | 135 | 467 |
| 32 h up | 1 | 7 | 1 | 14 | 37 | 54 | 6 | 0 | 4 | 0 | 26 | 43 | 0 | 193 | 534 |
| 4 h down | 1 | 1 | 1 | 0 | 0 | 6 | 2 | 0 | 0 | 0 | 1 | 4 | 0 | 16 | 52 |
| 8 h down | 1 | 12 | 2 | 3 | 36 | 23 | 15 | 8 | 4 | 32 | 24 | 52 | 129 | 341 | 3,273 |
| 16 h down | 1 | 7 | 1 | 1 | 48 | 12 | 3 | 8 | 0 | 10 | 1 | 8 | 4 | 104 | 638 |
| 32 h down | 0 | 6 | 0 | 0 | 49 | 10 | 3 | 33 | 0 | 19 | 1 | 6 | 5 | 132 | 545 |
At each time point, each probe set with significantly changed (false discovery rate < 5%) expression was screened against the Flyatlas.org expression dataset, and the tissue with maximum expression of that probe set was identified. The total scores for each tissue were then compared with the profile obtained from all genes in FlyAtlas, and χ2 was calculated. For 12 d.f., the critical value of χ2 is 21, so the genes up- and downregulated at all time points are significantly nonrandomly drawn from the different tissues: specifically, excretory system (tubule and hindgut, shown in bold) genes are massively overrepresented. Abbreviations for tissues: tag, thoracicoabdominal ganglion; acc, accessory gland; car, carcass; l_fat, larval fat body; fly, whole fly. Details of the FlyAtlas dataset have been published previously (11).