13-loci STR multiplex system for Brazilian seized samples of marijuana: individualization and origin differentiation

An initial exploration of machine learning for establishing associations between genetic markers and THC levels in Cannabis sativa samples

Cannabis sativa, a globally commercialized plant used for medicinal, food, fiber production, and recreation, necessitates effective identification to distinguish legal and illegal varieties in forensic contexts. This research utilizes multivariate statistical models and Machine Learning approaches to establish correlations between specific genotypes and tetrahydrocannabinol (Δ9-THC) content (%) in C. sativa samples. 132 cannabis leaves samples were obtained from legal growers in Piedmont, Italy, and illegal drug seizures in Turin. Samples were genetically profiled using a 13-loci STR multiplex and their Δ9-THC content was detected through quantitative GC-MS analysis. This study aims to assess the use of supervised classification modelling on genetic data to distinguish cannabis samples into legal and illegal categories, revealing distinct clusters characterized by unique allele profiles and THC content. t-distributed Stochastic Neighbor Embedding (t-SNE), Random Forest (RF) and Partial Least Squares Regression (PLS-R) were executed for the machine learning modelling. All the tested models resulted effective discriminating between legal samples and illegal. Although further validation is necessary, this study presents a novel forensic investigative approach, potentially aiding law enforcement in significant marijuana seizures or tracking illicit drug trafficking routes.

Cannabis sativa L. from Seized Drug Material: In Vitro Germination and Establishment

Background: With the expansion of the cannabis-derived product market, there is a growing need for seedling development to produce raw material for pharmaceutical applications and medicinal research. However, cannabis cultivation is illegal in many countries, and legal producers do not sell cannabis seeds in these countries. In Brazil, cannabis is still illegal, and the only way to obtain access to cannabis plants for research or as medicine is through importation, which is costly and requires authorization from the National Health Surveillance Agency (ANVISA), or from material seized by the police from drug trafficking. Methods: Therefore, since cannabis seeds obtained from drug trafficking have never been tested regarding their viability and use in in vitro cultivation, the aim of this study was to analyze the in vitro establishment of cannabis from seeds derived from Brazilian drug trafficking seizures that were provided by the police to investigate seed disinfestation procedures and further multiplication of nodal segments, with the purpose of obtaining material for medicinal research in the country. Seeds were subjected to four disinfestation treatments. Results: The best disinfestation treatment consisted in submerging the seeds in a 2 g·L-1 Captan® solution for 30 min before following the standard procedure with 70% ethanol for 30 sec and then 20 min in 2.5% sodium hypochlorite. The in vitro establishment of cannabis from seeds originating from Brazilian drug trafficking seizures was successful. The germination rate ranged from 10% to 90% according to the sample material. Non-brick weed, which consisted of dry leaves, stalks, and flowers, was more suitable for seed extraction and germination. Clones originating from BW4b showed the best development results compared with others. Conclusions: This is the first report of in vitro cannabis use in Brazil and opens great prospects for future work on its cultivation and research for medicinal applications in the country without relying on seed importation.

Evidence of the Ability of Microsatellite Method to Distinguish Cannabis Strains with High Cannabinoid Content

Introduction: Cannabis is a plant with high potential for use in several sectors of the industry; however, it is also a controversial crop due to its tetrahydrocannabinol (THC) content. Moreover, the plant has a rather unclarified classification. Traditionally, two types of Cannabis have been distinguished, hemp as a source of fiber and low THC content, and marijuana with high THC levels, which is used as a drug. With the increasing use of CBD strains and wide range of commercially used THC strains, it is becoming paramount to be able to develop an easy and reliable method for Cannabis strain differentiation. The use of simple sequence repeat markers, or microsatellites, seems to be an applicable choice. Materials and Methods: In this study, 52 strains of Cannabis with variable cannabinoid content were collected from growers from different geographical regions and analyzed using 17 different microsatellite markers. For more precise differentiation, five strains were selected and a higher number of individuals of each were analyzed. Results: Fragment analysis and cluster analysis showed that when one to three individual plants per strain were analyzed, the method was able to classify these samples into distinguishable groups with similar gene structure. They also revealed that when a larger sample set was used (10 individual plants per strain), highly specific strain clusters could be fully discriminated. Conclusion: Our study involved the highest number of cannabinoid-rich strains up to now and showed that the microsatellite method can be used to reliably differentiate Cannabis strains and show their relationships.

Characterization and evaluation of nine Cannabis sativa chloroplast SNP markers for crop type determination and biogeographical origin on European samples

Cannabis sativa can be classified in two main types, according to psychotropic cannabinoid ∆9-tetrahydrocannabinol (∆9-THC) content: the drug-type and the fiber-type. According to the European Monitoring Center for Drugs and Drug Addiction, most of the European Union countries consider the possession of cannabis, for personal use, a minor offense with possibility of incarceration. Despite of the model of legal supply (i.e., Spanish cannabis clubs, Netherlands coffee shops) or medical use (i.e., Italy), cannabis remains the most used and trafficked illicit plant in the European Union. Differentiating cannabis crops or tracing the biogeographical origin is crucial for law enforcement purposes. Chloroplast DNA (cpDNA) markers may assist to determine biogeographic origin and to differentiate hemp from marijuana. This research aims: to identify and to evaluate nine C. sativa cpDNA polymorphic SNP sites to differentiate crop type and to provide information about its biogeographical origin. Five SNaPshot™ assays for nine chloroplast markers were developed and conducted in marijuana samples seized in Chile, the USA-Mexico border and Spain, and hemp samples grown in Spain and in Italy. The SNapShot™ assays were tested on 122 cannabis samples, which included 16 blind samples, and were able to differentiate marijuana crop type from hemp crop type in all samples. Using phylogenetic analysis, genetic differences were observed between marijuana and hemp samples. Moreover, principal component analysis (PCA) supported the relationship among hemp samples, as well as for USA-Mexico border, Spanish, and Chilean marijuana samples. Genetic differences between groups based on the biogeographical origin and their crop type were observed. Increasing the number of genetic markers, including the most recently studied ones, and expanding the sample database will provide more accurate information about crop differentiation and biogeographical origin.

Understanding Cannabis sativa L.: Current Status of Propagation, Use, Legalization, and Haploid-Inducer-Mediated Genetic Engineering

Cannabis sativa L. is an illegal plant in many countries. The worldwide criminalization of the plant has for many years limited its research. Consequently, understanding the full scope of its benefits and harm became limited too. However, in recent years the world has witnessed an increased pace in legalization and decriminalization of C. sativa. This has prompted an increase in scientific studies on various aspects of the plant’s growth, development, and use. This review brings together the historical and current information about the plant’s relationship with mankind. We highlight the important aspects of C. sativa classification and identification, carefully analyzing the supporting arguments for both monotypic (single species) and polytypic (multiple species) perspectives. The review also identifies recent studies on suitable conditions and methods for C. sativa propagation as well as highlighting the diverse uses of the plant. Specifically, we describe the beneficial and harmful effects of the prominent phytocannabinoids and provide status of the studies on heterologous synthesis of phytocannabinoids in different biological systems. With a historical view on C. sativa legality, the review also provides an up-to-date worldwide standpoint on its regulation. Finally, we present a summary of the studies on genome editing and suggest areas for future research.

Development and Validation of a Novel and Fast Detection Method for Cannabis sativa: A 19-Plex Short Tandem Repeat Typing System

In recent years, influenced by the legalization of Cannabis sativa in some countries and regions, the number of people who smoke or abuse C. sativa has continuously grown, cases of transnational C. sativa trafficking have also been increasing. Therefore, fast and accurate identification and source tracking of C. sativa have become urgent social needs. In this study, we developed a new 19-plex short tandem repeats (STRs) typing system for C. sativa, which includes 15 autosomal STRs (D02-CANN1, C11-CANN1, 4910, B01-CANN1, E07-CANN1, 9269, B05-CANN1, H06-CANN2, 5159, nH09, CS1, ANUCS 305, 3735, and ANUCS 302 and 9043), two X-chromosome STRs (ANUCS 501 and 1528), one sex-determining marker (DM016, on Y-chromosome), and a quality control marker (DM029, on autosome). The whole polymerase chain reaction (PCR) process could finish within 1 h, making the system suitable for fast detection. The PCR products were detected and separated with an Applied Biosystems 3500XL Genetic Analyser. Developmental validation studies indicated that the 19-plex typing system was accurate, reliable and sensitive, which could also deconvolute mixed C. sativa samples. Specifically, the sensitivity study showed that a full genotyping profile was obtainable with as low as 125 pg of C. sativa DNA. The species specificity study demonstrated that this multiplex has no cross-reactivity with common non C. sativa DNA. In the population study, a total of 162 alleles at 15 autosomal STRs and 14 alleles at two X-chromosome STRs were detected among 85 samples. The efficiency parameters, including the total discrimination power (TDP) and the combined power of exclusion (CPE) of the system, were calculated to exceed 0.999 999 999 999 988 and 0.998 455 889 684 078, respectively, further proving that the system could meet the needs of individual identification. To the extent of the known studies, this is the first study that included the C. sativa sex-determining marker. In conclusion, the developed new 19-plex STR typing system can successfully achieve the purposes of species identification, gender determination, and individual identification, which could be a powerful tool in tracing trade routes of particular drug syndicates or dealers or in linking certain C. sativa to a crime scene.

Microbiomes in forensic botany: a review

Fragments of botanical material can often be found at crime scenes (on live and dead bodies, or on incriminating objects) and can provide circumstantial evidence on various aspects of forensic investigations such as determining crime scene locations, times of death or possession of illegal species. Morphological and genetic analysis are the most commonly applied methods to analyze plant fragment evidence but are limited by their low capacity to differentiate between potential source locations, especially at local scales. Here, we review the current applications and limitations of current plant fragment analysis for forensic investigations and introduce the potential of microbiome analysis to complement the existing forensic plant fragment analysis toolkit. The potential for plant fragment provenance identification at geographic scales meaningful to forensic investigations warrants further investigation of the phyllosphere microbiome in this context. To that end we identify three key areas of future research: 1) Retrieval of microbial DNA of sufficient quality and quantity from botanical material; 2) Variability of the phyllosphere microbiome at different taxonomic and spatial scales, with explicit reference to assignment capacity; 3) Impacts on assignment capacity of time, seasonality and movement of fragments between locations. The development of robust microbiome analysis tools for forensic purposes in botanical material could increase the evidentiary value of the botanical evidence commonly encountered in casework, aiding in the identification of crime scene locations.

Evaluation of two 13-loci STR multiplex system regarding identification and origin discrimination of Brazilian Cannabis sativa samples

According to the Brazilian Federal Police (BFP), the Brazilian Cannabis sativa illicit market is mainly supplied by drugs originated from Paraguay and Northeastern Brazil (Marijuana Polygon region). These two known routes, the increasing indoor cultivations (supported by online market), and drugs from Uruguay are also in BFP's sight. Forensic tools to aid police intelligence were published in the past years. In genetics, microsatellites have gained attention due to their individualization capability. This study aims to evaluate the effectiveness and efficiency of two STR multiplex systems previously proposed in 94 Cannabis sativa samples seized in Brazil. Principal coordinate analyses (PCoA), forensic parameters, and genetic structure analysis were executed. Both panels were effective in individualizing and origin discriminating all samples, and the system proposed in 2015 demonstrated better results. For this marker set, the probability of identity for a random individual is approximately one in 65 billion; also, the PCoA shows a clear genetic distinction among samples according to its origin. Bayesian inference populational structure analysis indicated a significant genetic diversity among seizure groups, matching with its origin. Overall, the STR multiplex systems were able to achieve its purpose in individualizing and differentiating, according to geographic region, Brazilian Cannabis sp. samples.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Whole Plastome Sequences of Two Drug-Type Cannabis: Insights Into the Use of Plastid in Forensic Analyses

DNA is one of the fastest growing tools in forensic sciences, increasing reliability in forensic reports and judgments. The use of DNA has increased in different areas of the forensic sciences, such as investigation of plant species, where plastid DNA has been used to elucidate and generate evidence in cases of traceability of genetically modified and controlled plants. Even with several advances and the practice of using DNA in forensic investigations, there are just few studies related to the identification of genetic tools for the characterization of drug and nondrug-types of Cannabis. Herein, the whole plastomes of two drug-type Cannabis are presented and have their structures compared with other Cannabis plastomes deposited in the GenBank, focusing in the forensic use of plastome sequences. The plastomes of Cannabis sativa "Brazuka" and of the hybrid Cannabis AK Royal Automatic presented general structure that does not differs from the reported for other C. sativa cultivars. A phylogenomic analyses grouped C. sativa "Brazuka" with the nondrug C. sativa cultivars, while the hybrid Cannabis AK Royal Automatic placed isolated, basal to this group. This suggests that the analysis of plastomes is useful toward genetic identification of hybrids in relation to C. sativa.