Table 1. The major transcription factors involved in SG specification, maintenance, morphogenesis, survival and secretion and their orthologues in humans and major model systems.
The genes involved in SG specification are among the most highly conserved, whereas the genes involved in regulating secretory content are among the least conserved. CrebA and it orthologues are among the few SG TF genes that have been demonstrated to have the same functions in increasing secretory capacity in mammals based on functional characterization of mutant phenotypes within each species (mice and humans) and/or their ability to regulate the same targets when expressed in Drosophila embryos.
| SG Specification | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Drosophila melanogaster | Arabidopsis thaliana | Dictyostelium discoideum | Saccharomyces cervisaie | Caenorhabditis elegans | Anopheles gambiae | Aedes aegypti | Ciona intestinalis | Homo sapiens | ||||
| Scr | Hox 20 | G0284293 | Very weak homology to mating type regulators | lin-39 | AGAP004659 | AAEL009949 | Hox5 | HoxA5 | HoxB5 | HoxC5 | ||
| % query cover | 10% | 15% | 29% | 100% | 100% | 25% | 21% | 36% | 27% | |||
| % identity | 52% | 35% | 53 | 48% | 51% | 66% | 72% | 50% | 63% | |||
| E value | 2.00E-05 | 3.00E-05 | 1.00E-33 | 1.00E-111 | 7.00E-107 | 8.00E-44 | 5.00E-44 | 3.00E-43 | 8.00E-42 | |||
| exd | knotted-like/BEL1-like | G0272967 | Tos8P | Cup9P | ceh-20 | AGAP004696 | exd | TF protein | Pbx1 | Pbx2 | Pbx3 | Pbx4 |
| % query cover | 26%/16% | 15% | 21% | 14% | 87% | 100% | 100% | 81% | 92% | 81% | 92% | 75% |
| % identity | 32/42% | 41% | 38% | 47% | 59% | 85% | 85% | 72% | 76% | 79% | 74% | 75% |
| E value | 1.00E-08 | 1.00E-07 | 1.00E-09 | 8.00E-09 | 1.00E-132 | 0 | 0 | 9.00E-143 | 6.00E-172 | 2.00E-166 | 2.00E-166 | 2.00E-156 |
| hth | AT1G69890 | G0280473 | Tos8P | Cup9P | unc-62 | AGAP002178 | hth | TF protein | Meis1 | Meis2 | Meis3 | |
| % query cover | 13% | 13% | 17% | 13% | 63% | 100% | 49% | 78% | 95% | 95% | 58% | |
| % identity | 57% | 54% | 44% | 47% | 48% | 72% | 85% | 52% | 52% | 53% | 73% | |
| E value | 5.00E-17 | 5.00E-15 | 4.00E-15 | 4.00E-13 | 1.00E-49 | 0 | 2.00E-145 | 1.00E-109 | 6.00E-128 | 8.00E-127 | 4.00E-60 | |
| SG Morphogenesis | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| hkb | Zn finger C2H2 | Zn finger C2H2 | Azf1p | Crz1p | EGR homolog | AGAP004517 | Zn finger 623 | Zn fing.132 | Kr-like 10 | Sp5-like | TF SP5 | Other TF-SP | Kr-like TFs |
| % query cover | 32% | 32% | 27% | 37% | 28% | 100% | 100% | 30% | 57% | 49% | 37% | 28–41% | 26–42% |
| % identity | 40 % | 46% | 47% | 36% | 48% | 46% | 49% | 47% | 35% | 48% | 52% | 44–50% | 39–49% |
| E value | 5.00E-11 | 3.00E-14 | 2.00E-17 | 1.00E-16 | 4.00E-21 | 9.00E-76 | 5.00E-83 | 2.00E-22 | 3.00E-22 | 9.00E-22 | 4.00E-23 | E-21 - E-22 | E-21/E-22 |
| SG Morphogenesis, Maintenance of SG expression, Suppression of duct genes, SG cell survival, Secretome | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| fkh | No clear orthologue | No clear orthologue | Hcm1p | Fkh2 | pha-4 | AGAP001671 | fkh | FoxA1-A | FOXA2 | FOXA1 | FOXA3 |
| % query cover | 17% | 15% | 39% | 89% | 91% | 28% | 24% | 36% | 22% | ||
| % identity | 49% | 46% | 51% | 65% | 64% | 72% | 85% | 65% | 81% | ||
| E value | 8.00E-18 | 8.00E-17 | 1.00E-58 | 2.00E-180 | 6.00E-179 | 1.00E-65 | 4.00E-75 | 1.00E-72 | 2.00E-63 | ||
| SG cell survival, Secretome | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| sage | No clear orthologue | No clear orthologue | No clear orthologue | ndf-1 | hlh-6 | AGAP013335 | LOC5578695 | TF protein | Mesp2 | Ngn3 | Mesp1 |
| % query cover | 22% | 23% | 25% | 27% | 41% | 20% | 23% | 20% | |||
| % identity | 47% | 41% | 74% | 72% | 31% | 51% | 48% | 51% | |||
| E value | 3.00E0–8 | 6.00E-07 | 1.00E-29 | 7.00E-32 | 2.00E-05 | 5.00E-09 | 1.00E-08 | 1.00E-08 | |||
| SG cell survival, Secretome | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Sens | Zn finger C2H2 | Zn finger C2H2 | Azf1p | F45B8.4 | AGAP010926 | sens | fez Zn finger 2-like | Gfi-1b | Gfi-1 |
| % query cover | 20% | 24% | 21% | 21% | 48% | 61% | 19% | 20% | 20% |
| % identity | 35% | 39% | 36% | 83% | 86% | 86% | 83% | 85% | 87% |
| E value | 6.00E-10 | 6.00E-19 | 4.00E-21 | 1.00E-64 | 9.00E-69 | 1.00E-69 | 1.00E-58 | 1.00E-63 | 7.00E-63 |
| Secretory capacity increases | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CrebA | bZIP TF | No clear orthologue | No clear orthologue | crh-2 | AGAP011038 | CrebA | TF protein | CREB3L1 | CREB3L2 | CREB3L3 | CREB3L4 | CREB3 |
| % query cover | 11% | 21% | 96% | 60% | 25% | 21% | 36% | 20% | 20% | 20% | ||
| % identity | 40% | 54% | 45% | 50% | 55% | 62% | 49% | 53% | 52% | 53% | ||
| E value | 1.00E-04 | 2.00E-29 | 4.00E-80 | 4.00E-62 | 4.00E-36 | 6.00E-34 | 5.00E-25 | 2.00E-25 | 5.00E-26 | 2.00E-22 | ||