Yet despite being made of similar ingredients, DNA and RNA are quite different. This is because DNA uses a different sugar than RNA (deoxyribose versus ribose) to join its alphabet. DNA is rigid and stable, double-stranded, and assumes a beautiful staircaselike structure. RNA is floppy and unstable, usually single-stranded, and sometimes tangles up into knots. These sister molecules have completely different personalities.
Researchers have known for decades that DNA stores our body plans—genetic information that is passed on through generations. They thought that RNA was merely a middleman, helping translate the DNA into proteins that do most of the work in the body. (If DNA is the blueprint, proteins are both contractors and building materials.) But it is time for mighty DNA to move aside. Beginning with the discovery of RNAi, researchers now realize that RNA is at least as important as DNA, if not more so.
Running Interference
RNAi is a natural gene-silencing process that has been preserved as a survival tool throughout billions of years of evolution. This gene-silencing effect was described decades ago—after a series of frustrating failed experiments—and today, at long last, its mechanism is known. RNAi brutally hijacks a special form of RNA that is doubled up, cleverly termed double-stranded RNA, and chops it into bits like a serial killer getting rid of a body!
This is useful to the cell in many ways. For example, double-stranded RNA, otherwise rare, is a common component of many viruses. Virus-infected plants sense the wrongful presence of double-stranded RNA, and set RNAi in motion—recruiting a series of protein machines to interfere with the rogue invader’s dastardly plans by slicing up its genes.
Interfere is too gentle a term since RNAi works through a molecular machine, descriptively named dicer, that cleaves double-stranded RNA into much smaller pieces. Those broken fragments are worse than useless to the virus, because they stick to other viral RNAs, gumming up their ability to schedule production time on protein-making ribosome factories.
RNAi dicer destroys viral RNA; no RNA means no new viruses and a healthy plant.
Today, researchers have unearthed RNAi in virtually every organism, from plants to pandas to people The payoff is a revolution in medical research, leading the way to cures and treatments for a wide range of troublesome diseases.
Tough Tobacco and the Petunia Boondoggle
The RNAi epic begins in 1928 with, of all things, tobacco.
As published in the wildly popular Journal of Agricultural Research , a scientist who infected a tobacco seedling with the deadly tobacco ring-spot virus didn’t succeed in knocking it off (and this was years before we knew the evils of smoking). Try as he might, this researcher could not kill the plant with a supposedly deadly virus. Repeated infections had only a minuscule effect, shriveling the plant’s bottom leaves. Wha . . . ? Why was it stubbornly thriving? What was protecting this tough tobacco?
Fast-forward more than a half century and now the patient is a petunia. The protagonists are two plant researchers aiming to beef up the petunia’s drab purpleness by giving it a scientific booster shot of color. In molecular-speak, they were supplementing the purple petunia with an additional pigmentation gene.
Well, it didn’t work out. Adding this “purpling gene” did not beef up the petunia’s purpleness. Instead the puzzled plant scientists discovered that more is less, and their gene-gineered petunia flowers were plain-Jane white, or at best, splotchy. The hell . . . ? Why are the petunias white? What a boondoggle!5
Oblivious to the commercial windfall of dye-ready petunias, the curious researchers plodded on, searching fruitlessly for a reason behind this perplexing failure.
Smashed Dogma?
The frustrating dilemma in both instances was that the results seemingly violated scientific dogma, firmly established before we were born!
Math-religion guru Gregor Mendel worked alone in his bucolic monastery, making history with simple equipment available to any 1800s gardener. Mendel deciphered the rules for how genes from two pea parents combine, then transmit traits to their offspring. Today, Mendelian genetics explain why your hair is as frizzy and unruly as your mother’s and her father’s.
Mendel’s laws form the basis of modern genetics and are the motive behind today’s $40 billion biotech industry. But the petunia just didn’t fit. The experimental results did not follow Mendel’s laws. Oh no-sies! Talk about a fast track to career failure.
But it was not quite as intractible as an NP-Complete problem.6 The answer arrived, although it took its own sweet time. This time, it is the 1990s and a new set of researchers are focused on the age-old mystery, “How do genes drive muscle development in roundworms as they grow in a petri dish?”
The worm scientists’ plan was to use a biotech trick to wipe out a particular worm muscle gene and witness what happens to the worms without that gene. But the scientists ran into a snag. Results were the opposite of expected! Adding a “control blank” (RNA that was supposed to do nothing) also wiped out the gene. Arghhh. What in tarnation was going on?
This time, perseverance paid off. A series of carefully planned tests explained the impossible result and finally unveiled the workings—mechanism, gears, and cogs—of gene silencing. It was RNAi. Earning the 2006 Nobel Prize for their work, Dr. Andrew Z. Fire and Dr. Craig C. Mello revealed that RNA itself, folded into a double-stranded knot, was the trigger for RNAi to shut down specific genes.
Now it all made sense.
RNAi to the Rescue: Making Sense of Petunias
In the Case of The Purple Petunia, the purple pigment gene would have obeyed Mendel’s rules, but that gene was being ignored: Its RNA messenger had been chopped into bits by RNAi. In the Case of The Virus-Resistant Tobacco, RNAi diced up the menacing ring-spot virus, a virus that otherwise would have stunted and killed the plant.
Molecular biologists are now convinced that RNAi protects things that can’t run away, like a tobacco plant. But they are less clear on the biological reasons for RNAi to exist in mammals, including us. One theory—backed by a mounting arsenal of evidence—is that RNAi serves as guardian of our genome by restricting the philandering of traveling viruses and other mobile segments of DNA that might go cavorting from one place to another. Genes in the wrong place create big messes—including many diseases—and RNAi may be our body’s way of keeping things tidy.
RNAi: Guardian of Our Genome
RNAi: The gene broom, sweeping away suspicious fragments of RNA.
Imagine! What might RNAi be enlisted to do?
Imagine how many wonderful things we can do with a tool that destroys target genes!
Scientists are learning to use RNAi as a tool to eliminate the genes we dread, in tumors, diseased cells, HIV infections, and so forth. Imagine RNAi used as a specific and safe natural pesticide! Imagine custom RNAi sprays that eradicate crop infections slaughter mosquitoes, or make tastier lettuce! And admit it, couldn’t lettuce use a tasty-spray?
Maybe it’s time to revisit the purple petunia.
REFERENCES:
D. Baulcombe, “RNA silencing in plants (Review),” Nature 431 (2004), 356 -363.
National Institute of General Medical Science, “RNA interference fact sheet,” http://www.nigms.nih.gov/News/Extras/RNAi/factsheet.htm.
G. L. Sen and H. M. Blau, “A brief history of RNAi: The silence of the genes (Review),” FASEB 9 (2006), 1293 -1299.
The 2006 Nobel Prize in Physiology or Medicine, “Advanced information, RNA Interference,” http://nobelprize.org/nobel_prizes/medicine/laureates/2006/adv.html.
CHAPTER 8
PRIVATE PARTS: CAUGHT WITH THEIR PANTS DOWN
“A friend told me, when I get depressed, just look up the Darwin Awards and I will feel better. Boy was he right!”
Placing one’s privates in predicaments is a common fast track to a Darwin Award. We lead off with two stories regarding scatology, follow up with two rare “living winners,” and end with four suspicious sex acts. Darwin delivers well-deserved kudos to the creatively kinky!
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br /> Dying to Go • Short Circuit • Muffled Explosion • Bitter Biter Bit a Nitwit • Bench Press • Pipe Cleaner • Single Bud Vase • Battered Sausages
Also see Tennessee Pee, p. 184, and Rub the Mint, p. 199.
Darwin Award Winner: Dying to Go
Confirmed by Darwin
Featuring urine, alcohol, and falling!
12 APRIL 2008, FLORIDA | Traffic was moving slowly on south-bound I-95. Shawn M. had recently left a Pompano Beach bar, and now he was stuck in traffic. As the saying goes, you don’t buy beer—you just rent it, and Shawn couldn’t wait another moment to relieve himself. “I need to take a leak,” he told his friends.
Traffic was deadlocked, so the waterlogged man climbed out, put his hand on the divider, and jumped over the low concrete wall for a little privacy . . . only to fall sixty-five feet to his death. “He probably thought there was a road, but there wasn’t,” said a Fort Lauderdale police spokesman. The car was idling on an overpass above the railroad lines.
His mother shared her thoughts. “Shawn didn’t do a whole lot for a living. He got along on his charm, just like his father.” Though his death was tragic, Shawn’s downfall proves the old adage: Look before you leak!
Reference: South Florida Sun Sentinel; The Miami Herald
Reader Comments
“Guess he was dying to go.”
“He shoulda peed in a bottle.”
“That’s why they call it Flori-duh.”
“Apparently it was just his time to go.”
“Now here’s a wee joke.”
“I wonder if he wet his pants from fright!”
At-Risk Survivor: Look Before You Leak
In a related story, a personal account, this time not fatal . . .
SUMMER 2003, USA | “I hired several laborers to prepare a garden area for me. They needed some supplies, so I showed them the location of ice water and the bathroom, and left to obtain the supplies. Upon my return, I found an ambulance in front of my home, along with two police cars. The police informed me that the neighbor had dialed 911 to report a naked man screaming and running around the yard.
My yard!
As it turned out, one of the laborers had needed to answer the call of nature. Rather than use the indoor bathroom, he went into the woods behind the house, dropped his trousers, and squatted down—right on top of a nest of hornets! He was released from the hospital about a week later, having learned a very painful and nearly fatal lesson: Always watch where you go!
“Watch where you are going—and look before you leak!”
Reference: Cy Stapleton
Darwin Award Winner: Short Circuit
Confirmed by Darwin
Featuring feces, a criminal, and electricity
MARCH 1989, SOUTH CAROLINA | Michael Anderson Godwin was a lucky murderer whose death sentence had been commuted to life in prison. Ironically he was sitting on the metal toilet in his cell and attempting to fix the TV set when he bit down on a live wire—and electrocuted himself!
Ironie des Schicksals (Irony of Fate)
Reference: News of the Weird, Gizmodo.com
Reader Comments
“I suppose he ended up in the netherworld.”
“His last name predicted his fate: God wins.”
Darwin Award Winner: Muffled Explosion
Confirmed by Darwin
Featuring gonads, explosions, machismo, and a living Darwin!
10 JANUARY 2009, PENNSYLVANIA | An embarrassed and seriously injured seventeen-year-old initially claimed that an explosive had been planted in his backpack by persons unknown. However, police investigators soon extracted the truth. He had found an M-80 explosive at his grand-mother’s house, taken it to his room to “examine” it, and began to repeatedly light and extinguish the fuse.
Commonly thought to be a quarter stick of dynamite, M-80s (according to pyrouniverse.com) actually contain 1/50 the amount of explosive (3 grams) and use flash powder rather than TNT. Used by the U.S. military to simulate grenade explosions, M-80s were outlawed in 1966 under the Child Protection Act. They are not safe enough to be detonated by the average man on the average street, let alone by an average seventeen-year-old in an average bedroom.
During one of these cycles the fuse would notgo out, so he jammed the red cardboard tube between his thighs and covered it with his hand to muffle the explosion. This plan was less successful than he had hoped.
One loud KABOOM! later, our junior pyrotechnics specialist had lost his right hand and right leg. It is not known whether the injury also affected his ability to reproduce, but if it had, the fellow would be eligible to compete for the honor of a living Darwin Award.
Reference: WPXI News; Pittsburgh Tribune-Review; pittsburghlive.com; Pittsburgh Post-Gazette
Reader Comments
“A new way to lose weight.”
“Stupidity, thy name is teenager!”
“A glimpse of America’s youth at its finest.”
WEIRD SCIENCE: BAND-AIDS!
Good news for competitorsduring their Darwin Awards tryouts!
Those competing for a Darwin Award often suffer a few nicks and dings along the way. Recently scientists designed medical sutures made from natural polymer excreted by helpful bacteria. Sutures made from these fibers are naturally absorbed by our bodies, so no more pulling stitches! Doctors report favorably on the flexible and easy-to-work-with sutures.
Bacterial polymers: a perfect human repair material
“Those whom life does not cure, death will.”
—Cormac McCarthy
Urban Legend: Bitter Biter Bit a Nitwit
Unconfirmed—Suspected Urban Legend
Featuring gonads and a raccoon!
Although this story was submitted dozens of times—citing news articles from Belgium, Denmark, Norway, Italy, Japan, and Australia—we classify this story as an urban legend, because the sole source of all these news reports is The Sun tabloid. If you have a reliable source confirming the story, please contact Darwin. www.DarwinAwards.com/contact
JANUARY 2009, RUSSIA | ARAG - ING RACCOON HAS BITTEN OFF A PERVERT’S PRIVATES AS HE WAS TRYING TO RAPE THE ANIMAL, screams the headline. When most of us see a wild animal, raping it never enters our minds. Why would it?
Alexander, forty-four, was on a drunken weekend with friends in Moscow when he leapt on the terrified animal. “When I saw the raccoon I thought I’d have some fun,” he told stunned casualty surgeons.
Although there was not much left to work with, plastic surgeons were trying to reconstruct his mangled manhood. If he is unable to procreate—he is eligible for a Darwin Award. But thus far no reports have “leaked” on the success of the shaft graft.
Reference: thesun.co.uk; FailBlog.org photo of a newspaper clipping
Reader Comments
“I hope it doesn’t work—I’m an animal lover.”
“Next time try a beaver.”
URBAN LEGEND: RACCOON ROCKET
Raccoons seem to be nuclei around which Urban Legends condense. For example, in rural Pennsylvania a group of men were drinking beer and discharging firearms at a raccoon that was wandering by. The animal escaped into a three-foot-diameter drainage pipe. Determined to smoke the animal out, one man retrieved a can of gasoline and poured some down the pipe. After several unsuccessful attempts to ignite the fuel, the determined dude proceeded to slide feet first, fifteen feet down the sloping pipe to toss the match. The subsequent rapidly expanding fireball propelled him back the way he had come, though at a much higher rate of speed. He exited the angled pipe “like a Polaris missile,” according to a witness, with “a Doppler effect to his scream as he flew over his house, followed by a loud thud” as he landed on his own front lawn.
Reference: Darwin Awards:
Evolution in Action (Plume, 2001)
At-Risk Survivor: Bench Press
Confirmed by Darwin
Featuring gonads!
6 AUGUST 2008 , HONG KONG | It’s raining. You’re lonely. Why not
? That was how forty-one-year-old Le Xing found himself facedown on a bench and calling for help in the middle of the night.
The lonely man had noticed that the steel sit-up benches in a local park had numerous ventilation holes and thought it might be possible to use them for sexual gratification.
Once Le Xing became aroused, he found he was stuck and could not remove himself from the hole in the bench. Quite understandably, he panicked. Police received a call from a disturbed man and arrived to find him trapped facedown on the bench.
Facedown on a bench and calling for help in the middle of the night . . .
Doctors were summoned to the scene. They tried every thing, but eventually, emergency workers had to cut the entire bench free and take both it and him to the hospital.
Four painful hours later, doctors finally separated man from bench. It is certainly possible that the lack of blood flow easily could have caused sufficient damage to require doctors to remove his penis. This is one bad date that Le Xing will never forget.
The Darwin Awards Countdown to Extinction Page 5