Mapping the world's entheogenic genomes.

In 1957, an account of Mazatec mushroom ceremony in the highlands of Oaxaca entered the American popular press, and within a decade psilocybin had become one of the most culturally consequential molecules of the twentieth century. It passed through Sandoz Laboratories, through the counterculture, through decades of prohibition, and eventually into the architecture of a new clinical discipline. By the time serious research resumed, the molecule was among the most discussed in all of pharmacology. The fungi that produce it remained, in most meaningful respects, unstudied.

This is a peculiar situation, as these organisms do not produce psilocybin alone. By way of a four-enzyme cluster, they turn tryptophan into psilocybin and its dephosphorylated tryptamine relatives: baeocystin, norbaeocystin, norpsilocin. Then, by an entirely separate biosynthetic route, they use that same amino acid to produce β-carbolines that reversibly inhibit monoamine oxidase A — the enzyme primarily responsible for degrading psilocin in the body. In other words, both the prodrug and a chemical brake on its metabolism, inside a single organism.

The genetics only make this more fascinating. The biosynthetic cluster that builds psilocybin is roughly sixty-seven million years old, arising near the Cretaceous–Paleogene boundary. It exists today in at least two distinct gene-order architectures, corresponding to the deepest phylogenetic split withinPsilocybe, which suggests the pathway may have been acquired more than once. More remarkably still, the entire cluster has jumped into unrelated mushroom lineages on at least four occasions since the Eocene.

And yet of the roughly one hundred and sixty-five accepted species in the genus, fewer than fifteen have a published genome assembly. For most of the wider group of psilocybin-producing fungi, the public molecular record is a single ITS barcode — or nothing at all. Neither the origin of this pathway nor its movement across forty million years of fungal evolution can be reconstructed without genomes. Our program's mission is to build the most comprehensive map of psilocybin-producing organisms: vouchered collection, multi-locus barcoding, whole-genome sequencing, and open deposition.