By Maya El-Moussaoui
The Genome Research Journal posted the long–awaited cannabis chromosome map, a great step towards more extensive cannabis research, which uncovers the plants evolutionary history and medical future. Researchers have discovered that an ancient virus on the plant’s genome is what created THC and CBD, its bioactive substances.
The findings also provided many other insights into the plant’s gene arrangement and breeding process. A new lesser known cannabinoid called CBC was discovered and found to have potentially psychoactive properties as well as anti-inflammatory benefits. Furthermore, breeding information can be revealed through this map to create the most efficient plant for medical or recreational use.
The research also analyses the difference between the two cannabis species, marijuana and hemp. While hemp is more potent in CBD (cannabidiol), which has been medically used for chronic pain, epilepsy and Alzheimer’s treatment, marijuana is more abundant in THC (tetrahydrocannabinol), its psychoactive component. Genes THCA and CBDA encode both THC and CBD respectively. Due to viruses that covered the genome millions of years ago, the enzymes are surrounded by an abundance of junky non-coded DNA. Once introduced into a host’s DNA, the retro elements replicate themselves and spread throughout the genome, either inserting themselves harmlessly into non-coding regions or producing mutations by interrupting the sequence of a gene. Therefore, due to the similarities of the genes at a DNA level, it is not clear if breeders can isolate CBD and THC completely for medical purposes.
The team concluded that THCA and CBDA were the same gene, and through duplication and scrambling over time eventually two separate enzymes were created.
The study was a three–part collaboration by scientists Tim Hughes, Jonathan Page from the University of British Columbia, and Harm Van Bakel from the Icahn School of Medicine at Mount Sinai in New York.
Tim Hughes states, “The chromosome map is an important foundational resource for further research which, despite cannabis’ widespread use, has lagged behind other crops due to restrictive legislation.”