Antheridiogen

[4] In this article, he explains the discovery of a molecule, which he titled "A-substanz", that caused premature formation of antheridia when agar media was reused after cultivation of Pteridium aquilinum.

In the second step, antheridiogens are taken up by neighboring gametophytes in the colony and undergoes a series of molecular changes that allow it to finally induce or suppress formation of antheridia or archegonia.

Studies performed on Ceratopteris richardii have proven that a growing gametophyte is only able to respond to its own antheridiogen for a brief period of time in very early stages of growth, and that if exposure is removed, undifferentiated cells can revert from male to hermaphrodite.

One study performed on the fern species Woodwardia radicans found that sex expression of mature gametophytes is dependent on stress conditions.

Although mammalian sex determination is decided by chromosomes, chemicals called pheromones are released, detected by the olfactory system, and can control social behaviors and hormone levels.