Antigen
The Antigen chemicals exist in several different varieties, numbered from 0 to 7 in C1. Like the antigens found on the surface of bacteria in the real world, antigens in the Creatures games can be found after bacterial infections.
For each type of antigen, there is a corresponding type of antibody, allowing the creature's immune system to produce the correct antibody against illnesses caused by bacteria. Production of antibodies uses up glucose, and without glucose, antibodies can't be made. (See Brian) In C1, the lower-numbered antigens (0 -4) would use more glucose to make antibodies, and the higher-numbered antigens (5 - 7) would use less glucose. In C1, antibodies would not react with antigens to reduce the concentration of antigens. LummoxJR developed some genes that would do this.
In C3/DS, in addition to differing levels of glucose consumption, production of antibodies can produce mildly toxic side-effects. (See ChiChi Norn Genome gene 346 onwards.) Note that the side effects can differ from genome to genome, for example, in general, the Magma Norns produce more coldness as a side effect, and they do not have hotness as a side effect. Antigens also attack certain organs - if the organs cannot be repaired, the genes governed by those organs switch off.
| Number | Side effect in C3 norn genome | Organs attacked in C3 norn genome |
|---|---|---|
| 0 | Histamine B | Kidney/bladder Muscles Painly drive overwhelmsion Uterus |
| 1 | Histamine A | Constitutive drive maintenance Liver catabolic Painly drive overwhelmsion Skin cooling function Uterus |
| 2 | Coldness | Constitutive drive maintenance Fearly drive overwhelmsion Gonad Liver catabolic Skin cooling function |
| 3 | Coldness | Central Nervous System: Drive lobe support Fearly drive overwhelmsion Fight or flight Gonad Regulation functions |
| 4 | Hotness | Central Nervous System: Drive lobe support Digestive functions Fight or flight Immune system Lung Regulation functions |
| 5 | Wounded | Digestive functions Floating loci Immune system Lung Mitochondrial function |
| 6 | Hotness | Bones Floating loci Liver anabolic Mitochondrial function |
| 7 | Pain | Bones Kidney / bladder Liver anabolic Muscles |
