Tag Archives: DNA

Blood and name calling

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He ain’t half heavy, he’s my half-brother – The Adopted Hollies

If you haven’t got a penny, then half a penny’ll do. If you haven’t got a ha’ penny, then God bless you. – some British thing (not the Hollies)

I read an article this weekend that described the murder of a man by his half-brother. Normally, I don’t read these kinds of stories, but I was drawn to this one because of the phrase half-brother, which made me wonder why this phrase was still in common use.

What the hell is a half brother? (Shawn, Scott, me)

What the hell is a half brother? (Shawn, Scott, me)

I appreciate that historically there may have been a reason to keep track of who one’s siblings were from a legacy perspective. Family homes and farms (and for the wealthy, estates) possibly hung in the balance when Dad died…although I question how often this was a concern. And no self-respecting Shakespearean comedy or drama would be complete without an evil half-brother. But why now?

To quote the Bard:

What’s in a name? that which we call a rose

By any other name would smell as sweet;

Likewise, to quote Merriam-Webster:

Blood (n): the fluid that circulates in the heart, arteries, capillaries, and veins of a vertebrate animal carrying nourishment and oxygen to and bringing away waste products from all parts of the body.

So again, I ask why the fixation on a surname and the concept of blood ties?

The last time blood ties mattered

The last time blood ties mattered

I never knew my father—not something I take personally; just a fact—and so I have no particular attachment to my last name aside from convenience and familiarity. I feel no compunction to continue the family name. Other people have the surname of Willis…let them continue it if they want.

And my brothers and I only share one common parent—our mom—and so have different surnames. Does this make them any less my brothers, however, than a pair of siblings who shared the genetic legacy of the same pair of parents (pairents)? Not for me (you’d have to ask them their perspectives on this).

For the famous, an argument can be made that sharing DNA somehow opens doors from one generation to the next: Ken Griffey Jr., Drew Barrymore, Robert Downey Jr., Robert Kennedy Jr., Paris Hilton.

Not sure how that last one works

Not sure how that last one works

But in most of those cases, sustained success comes from inherent talent and drive, not simply DNA. (I still don’t understand why Paris Hilton is famous.) Likewise, for every case of possible nepotistic success, there are hundreds or thousands of cases of success despite lineage (no disrespect to parents anywhere).

Perhaps I am the anomaly on this, but I simply don’t understand the importance of the nomenclature to who I am as an individual or how I respond to a family member versus a close non-genetically linked person (aka friend).

Agah, Nicholas and Marsha are my siblings despite the lack of genetic links

Agah, Nicholas and Marsha are my siblings despite the lack of genetic links

Scott and Shawn are my brothers more for our shared experiences than because of any genetic connection, much as Agah and Nicholas are my brothers and Marsha my sister for our shared affection and experiences.

Call me Ishmael, for all I care…if we are good friends, you have likely called me worse.

In the meantime, I’ll use my bloodlines to circulate oxygen to tissues and white cells to fight infection.

Brothers...no half-measures

Brothers…no half-measures

My preferred quote:

We few, we happy few, we band of brothers;
For he to-day that sheds his blood with me
Shall be my brother; be he ne’er so vile,
This day shall gentle his condition:

Left-handed (DNA) compliment

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While attending the surprise birthday party for a friend in the sciences, I noticed he owned a coffee mug from a group called Life Sciences Career Development Society based at the University of Toronto. Actually, to be more accurate, what caught my eye was the DNA double-helix on the mug…and the fact that it was wrong.

Wrong

BOOM! My head explodes.

As someone with biochemistry & genetics degrees who has written about the life sciences for ~15 years, this seemingly innocuous error drives me crazy. This must be how copy editors feel when they see a misused semi-colon (and I’m sorry about that).

right v wrong

For the non-biochemists, through a characteristic known as chirality (look it up…too hard to explain here), the typical DNA double-helix in human cells—the famous Watson-Crick-Franklin structure or B-DNA—has a right-handed helix. This means that if you could see the double-helix (above) and let your fingers follow along the curve of one side as it wraps around the other, you could only do this comfortably with your right hand.

You can see that in an example of a single helix that curves either to the left (left) or the right (right).

handed

Unfortunately, somewhere in the mists of science illustrations time, an artist drew the double-helix of DNA in the wrong direction and that double-helical abomination has perpetuated ad nauseum, including irritatingly enough, in science publications and scientific logos such as a recent health article in the Toronto Star (image below), the cover of a sci-fi novel and the LSCDS logo.

DNA - backwards

And if I only saw this in 50% of the images, I’d be irritated but probably not the raving loony I am now. But no, this freak of nature is everywhere. The correct right-handed DNA illustration is the anomaly.

So why does this matter? Maybe it doesn’t, and I am just a raving loony.

Certifiable loony!

Certifiable loony!

But for me, I struggle with what else might be wrong in a life science or healthcare story if they can’t get the DNA helix right. Do I trust the math of an investment planner who doesn’t know that four quarters equals one dollar?

Luckily, the fix is an easy one. Simply mirror the image you have (not turn it upside down) and the left-handed double-helix becomes a right-handed one. (In a mirror, your actual left hand looks like a right hand.)

So, medical illustrators everywhere, please fix your catalogues of scientific illustrations. My head can’t take too many more explosions.

So much better

Nerves already calming.

[Also, from a design perspective, up and to the right is more palatable for North American audiences as it implies future success (e.g., rising value). Has nothing to do with handedness, here.]

For the more biochemically savvy:

Yes, there is left-handed DNA, which is also known as Z-DNA. But as you can see from the illustration below, its structure is significantly different from the smooth-flowing curves of B-DNA (and the equally unusual A-DNA).

Two rights don't make a left

Two rights don’t make a left

Ergo ego

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(Property of evolution.berkeley.edu)

(Property of evolution.berkeley.edu)

Be as egocentric as you want, but always remember: You were one point mutation away from being somebody else.

(PS To the genetics nerds out there, I know they messed up the “original” strands in this diagram as the originals from different strands cannot be identical but rather should be complementary.)