This is how marijuana got its cannabinoids

The first complete map of the genome of the plant Cannabis sativa reveals the evolutionary past of this species, which had its cannabinoids or psychoactive substances through virus old women who infected her and infiltrated her DNA. This discovery, made by an international team of researchers and published in Genome Research, adds the discovery of the gene responsible for the production of cannabicyclohexine or CBC, a little-known cannabinoid, but recent research has indicated that it could have powerful anti-inflammatory properties.

The complete sequencing of the genetic material of this plant species opens the door to the cultivation of new therapeutic varieties without psychoactive effects. In addition, the researchers claim that this success allows to design varieties of this plant with more precise cannabinoid profiles and could allow to obtain marijuana varieties that are more productive, pest-resistant and require less water. and light, so more durable.

The complete sequencing of the genetic material of this plant species opens the door to the cultivation of new therapeutic varieties without psychoactive effects.

"The chromosomal map of Cannabis sativa is an important basic resource for further research.Despite the widespread use of cannabis, restrictive legislation on this species has delayed the study," said co-author Tim Hughes, researcher in molecular genetics at the University of Toronto.

Before this work, scientists knew little about how hemp, used for thousands of years for its resistant fibers, and marijuana, grown for consumption as a drug, both species from Cannabis sativa, could have such a variety . high cannabinoids

And it is that the first ones have flowers which contain a large quantity of substance with medicinal properties, the CBD, which is not psychoactive and which is used for relieving the pain, in the treatment of schizophrenia, the disease of d Alzheimer's or epilepsy. In contrast, the second, marijuana, selected and cultivated as a drug by humans, contains a lot of THC, a highly psychoactive substance.

The genome map obtained by the scientists for the first time reveals that the two substances, THC and CBD, come from the colonization of the partial genome by old viruses. To find out, the researchers sequenced the complete genome, made up of 10 chromosomes, from a hybrid plant obtained from the variety 'purple kush', grown to obtain drugs, and from a variety of plants. another medicinal variety called "finola".

By sequencing the genome, they have obtained a map with hundreds of millions of base pairs that shows that the enzymes (the proteins responsible for accelerating reactions in cells) that produce THC and CBD are encoded by the genes. THCA and CBDA synthase. The two researchers found that these genes are surrounded by "unwanted" DNA, which displays retro-elemental signals, sections of DNA integrated into the genome during evolution, from viruses infected with the virus. . various generations of Cannabis sativa ancestors. Once the viruses are introduced into the host's DNA, the retroelements replicate and pass to other regions of the genome. Sometimes they are inserted without damage into the non-coding regions and sometimes they introduce mutations.

The authors of the work consider that the genes at the origin of THC and CBD could come from a single precursor gene that would have doubled and that these two versions would have diverged slightly after the introduction of viruses. Moreover, after being cultivated by the man, the two copies diverged even more.

For the researchers, their results pave the way for growing varieties with a high content of CBD and no THC. At present, there is no variety of therapeutic use free of THC. Thus, creating a variety to zero with high content in CBD could be, according to the authors, a "revolution" for people suffering from epilepsy, anxiety, chronic pain

Some varieties contain a large amount of substance with medicinal properties, CBD, which is not psychoactive and which is used to relieve pain, in the treatment of schizophrenia, Alzheimer's disease or Alzheimer's disease. # 39; epilepsy.