Investigation of Genotype/chemotype Correlations in Cannabis Sativa

Abstract

Though Cannabis sativa has been used as a medical treatment for centuries, recent American political controversy surrounding the legalization of marijuana has generated interest into the mechanism of cannabinoid biosynthesis. This biosynthetic pathway involves enzymes derived from genes which produce the major cannabinoids of interest within C. sativa. ?9-Tetrahydrocannabinol (THC) has been predominant in investigations due to numerous reported beneficial effects for various symptoms such as those associated with cancer treatment. Non-synonymous single nucleotide polymorphisms (SNPs) within the THCA synthase gene responsible for enzymatic production of THC change the nucleotide sequence and subsequent amino acid sequence for the enzyme. These changes could potentially alter the efficacy of the enzyme that produces THC. In the current investigation, permission was granted by Oklahoma State University to handle small samples of C. sativa within the School of Forensic Science student laboratories. The Tulsa Police Department provided small samples of C. sativa seized previously and marked �to be destroyed�. In these samples, four single nucleotide polymorphisms within the THCA synthase gene were analyzed via SNaPshot� analysis and amplicon sequencing. The concentration of THC was determined using gas chromatography-mass spectrometry. Correlation statistics were performed to determine if a correlation existed between the concentration of THC and the activity of the THCA synthase gene. No correlation existed between THCA synthase SNP profiles and THC concentration. If a correlation existed, genetic analysis of the C. sativa THCA synthase would provide growers, providers, distributors, and users of medical marijuana with more pertinent information about the quality of C. sativa products available.