This gives a whole new meaning to high-throughput sequencing

The marijuana genome has been sequenced by researchers at the University of Toronto and University of Saskatchewan.

It’s actually a pretty neat study. They compared two strains of Cannabis sativa: Purple Kush (a “potent” strain used for getting high) and Finola (a hemp cultivar). From looking at the genome alone, researchers weren’t really able to find any striking differences. But then they turned to the transcriptome.

What the hell is that? Time for a quick flashback to high school biology! DNA is transcribed into messenger RNA. That mRNA leaves the nucleus and heads out into the cytoplasm, where ribosomes use it as a set of instructions on how to make protein. A “transcriptome” is all of the mRNA produced by an organism. And yes, it differs from a genome – some genes are highly expressed and produce lots of mRNA, others can be completely turned off, and many are somewhere in the middle. The quantity of mRNA is something marked in the transcriptome.

By looking at the transcriptome, they were able to find that Purple Kush exclusively expresses the gene involved in the production of THC, the psychoactive component of marijuana. The hemp strain, on the other hand, didn’t express this gene at all, despite having it in the genome.

You can check out a draft of the paper at Genome Biology, and even search through the marijuana genome here.

I think the most entertaining part is looking at all of the bad puns journalists are putting in titles. Though I have to take offense at Science’s introduction on their blog post:

Attendees at Burning Man, the famously free-wheeling yearly Nevada art gathering, don’t usually take note of new genomic sequences, but they may want to check out a paper published today in Genome Biology.

Maybe this is just because I’m in Seattle, but I’m pretty sure I’m in the minority in my field because I never tried pot. How dare they imply that stoners aren’t interested in genomics when they’re the ones sequencing the genomes. Especially when Francis Crick admitted to experimenting with LSD when he discovered the structure of DNA. Our field is apparently inspired by psychoactive drugs.


  1. Rex says

    Alcohol, weed and experimental sex are college requirements! You have been going to college for what like 15 years now?

    You have been neglecting part of the curriculum! Go! Now! Research and experiment!

    (the previous comment was for entertainment purposes only, and in no way is a real recommendation to break the law)

  2. Joel Grant says

    I am an old grampy now and have not smoked pot for decades. But I sure wish we had had known about this back then. These days, potheads have the opportunity to actually get really high. Back then, not so much.

  3. KarlVonMox says

    I’d like to offer a correction – “Transcriptome” does not refer merely to mRNA – but all RNA’s transcribed by the organism, including non-coding RNA’s such as ribosomal RNAs and transfer RNAs, as well as others. If you do a cool technique like RNA seq you can pick up all of these.

  4. Quatguy says

    Jen, if you ever want to consider yourself a westcoaster, you definately need to sample the bud. That being said, the American pot laws are probably a lot worse than they are in BC. You are not in Kansas anymore (Indiana, whatever), it is all the same to me.

  5. says


    They do vary state to state. I’m not sure what Washington’s rule is, but I know in California “medical marijuana” is almost a legal fiction. I live in Massachusetts, where the current law was passed by referendum to make pot a civil offense with a $100 fine… but the cop isn’t allowed to ID you to write the ticket. The law was structured to be unenforceable.

  6. hieropants says

    Nobody ever offered me alcohol, weed, or experimental sex in college! All I did was work. :(

  7. Pi Guy says

    – BS in Physics.
    – 10 years as Modeling and Simulation Analyst (played video games and wrote game summaries) in Chem-Bio Defense.
    – Currently working in IT for US Army.

    >> Daily* pot smoker.

    * “Daily” has been the goal limited by time, money, responsibilities, and availability but, with few protracted recesses, we’re talking over 30 years here.

    I’m not advocating that everyone should try. I like it but, then, I think that water is wet so what do I know? I’m just supporting Jen’s hypothesis that it’s not destroying every mind it touches.

    Damn it, dog – those Cheetos were my breakfast!

  8. melior says

    Especially when Francis Crick admitted to experimenting with LSD when he discovered the structure of DNA.

    How could you fail to mention the man that won the Nobel for inventing PCR?

    During a symposium held for centenarian Albert Hofmann, “Hofmann revealed that he was told by Nobel-prize-winning chemist Kary Mullis that LSD had helped him develop the polymerase chain reaction that helps amplify specific DNA sequences.”

  9. Jon says

    We know the gene that makes THC? And we have its sequence?

    Sooo, am I to assume that there’s no genetics lab that’s made a plasmid with the gene and thus created a THC-pumping bacteria?

  10. Arctic Ape says

    If I remember correctly, ‘Finola’ is practically the only modern hemp cultivar suitable for northern areas (it was bred in Finland). However, after recent legal development it’s impossible to grow in the EU because it sometimes does produce THC slightly over the very low legal limit.

  11. Gord says

    No surprise that it was done by Canadians… the only surprise for me was that it was U of T and Saskatchewan, rather than a collaboration among UBC, UVic and SFU. (I’m Canadian… and BC is the place to be for pot in Canada.)

  12. JM says

    I never did weed daily, but just about every weekend back in the ’70s. Then one night I came home from a party and decided to work on my statistics homework that I’d abandoned earlier as too difficult. It was easy when I was high. Just about scared me straight. And in those days in that place, what we were smoking was closer to hemp than the good stuff.

  13. wendyquinton says

    As a University of Saskatchewan Alum, it was interesting to see you comment on some of the research (even if is with pot LOL). Makes me think that what we do here in out little spot, gets out in the world. FYI there is nothing more fun going for beer and getting people to pronouce Saskatchewan while visiting in the States. “You are from Sask-a-what???”. :)

  14. stevecorbin says

    As an outsider, it seems to me that psychoactive drugs would be very helpful in studying biology – but maybe that’s just because biology already looks like an acid trip to me.

    I do rather like how every reporter, author, and TV anchor acts as though they’ve never done any drugs whenever they write about them. Statistics say a good portion of them have done drugs, and still do.

    It would be pretty cool if we could stop pretending that no one who takes recreational drugs (except alcohol, and maybe nicotine, and certainly caffeine) can be successful. I think if, instead of bullshit scare tactics, we’d been given actual, useful information about drugs and what they do as kids, fewer of us would end up going off the deep end with them. (Though I have nothing to back that up, so keep the salt handy.)

  15. says

    You are able to and will also be very proud of your successes when you properly pick your current homegrown pot. Keep the SECRET. Ever heard of envy? Breakup? Revenge? – Folks listen and constantly need to sense critical, never allow it to be his or her chit chat. Safeguard your investment * Shut-up.|

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