CRISPR: Another mystery of life.

The Joyce family, 1951

I think Linda had just pinched Carolyn

It is a gloomy day, today.  I feel sorry for the little kids who will be swarming the local sidewalks, paper bags in hand – it is Halloween, and it is raining.  But that’s the PNW.  I won’t be here to pass out candy, anyway; I am going to the movies, and then out to dinner.  They shouldn’t eat all that bad stuff, anyway.  Now, if I could only pass out bacon…..

But before the movie starts, I decided to do some work.  Specifically, I decided to really wrap my mind around the CRISPRCas9 business that I have alluded to before.  It is very important, no doubt about it.  For instance, when I went in search of information I asked Google Scholar to give me a list of articles containing the acronym CRISPR published in the last two years.  I got 18,000+ hits.  And, tragically, not one of them can I understand.  Even Wikipedia leaves me mired in impenetrable biochemical slop.  So I decided to first look at what I had had to say previously about CRISPR in this blog.  Here is the only informative blog. I urge you to re-read it.

http://ljb-quiltcutie.blogspot.com/2015/08/forget-frankinfoods-how-about-designer.html

Alternatively, you could go straight to the Economist article that inspired it:

http://www.economist.com/news/briefing/21661799-it-now-easy-edit-genomes-plants-animals-and-humans-age-red-pen

I can’t tell you how CRISPRCas9 works – because I don’t know – but I can tell you what it does.  It allows us (that is, we fallible humans) to cut the double-stranded DNA molecule precisely at any particular specified place.  Used properly, then, it should allow us to remove a gene we don’t want, and substitute a new and improved model.  The biological, ethical, and even economic consequences of this technology are enormous.  Learned discussions are ongoing.

So, how about ovarian cancer?  Well, it’s not mentioned specifically, but I can see some useful applications.  For instance: what if you come from a family that carries the BRCA mutations (and others that contribute to breast and ovarian cancer)?  Using CRISPR technology it should be possible to “edit” those mistakes out of the germ cells that you will pass to your offspring – and substitute a working copy of the gene.  So maybe you will still be subject to higher cancer odds, but your kids won’t.  That’s progress.   Also, it should be possible to “engineer” T-cells to attack cancer cells; in fact it already has been done with total success, in mice.  (Some scientist was once quoted as saying “If all we wanted was to cure cancer in mice, we’d be out of a job”.)

So, I can’t explain CRISPR technology to you, but even so the serious minded of you (surely most) will happily devote a half-hour or so to the subject.  Read the links, above.

Here are some study aides:

CRISPR stands for Clustered Regularly Interspersed Short Palindromic Sequences (now, wasn’t that a big help?)

Viruses reproduce by injecting their DNA into other cells, principally bacteria.  Bacteria have responded by evolving RNA molecules that “recognize” the virus DNA, and cut it out. CRISPR technology is based on this.  Not all viruses are bad.

A palindrome is a sequence that reads the same forwards or backwards.  Since we are talking about RNA, there are four “letters” to consider: a, c,, g, and u.  So here is an RNA palindrome:  aucggcua.  Thus a CRISPR RNA sequence might read something like this: aucggcua (some other stuff, “interspersed”) aucggcua (more interspersed stuff) aucggcua and etc.  Since the “Sequence” is “Short”, there aren’t too many of these things.  SOMEHOW this structure guides the CRISPR RNA to the proper spot, where it uses the enzyme Cas9 as a cutting tool.  How, I haven’t a clue.

Okay, you get a reprieve; my ride has arrived.  I am going to see “The Martian”, about a botanist stranded on Mars.  Sometimes I feel like a geologist stranded in an organic chemistry lab.

More on CRISPR if I ever figure it out.  Don’t hold your breath.