Get your clone uncontaminated
It’s not unusual for a paternity test to reveal unpleasant truths about the kiddy (and its genitor).
The outcome of a Texas paternity test in May, however, wasn’t only unusual - it was crazy. Here’s the story.
A mother and her fiancé decided to take a paternity test due to the puzzling different facial features of their 11-month-old children (a pair of twins). When confronted with the test’s results they cannot believe the unbelievable truth:
The mother has given birth to twins, but they are by different fathers. They have completely different DNA.
One child is the biological son of the mother’s fiancé, the second one is the outcome of an affair with another man she had at the time the twins were conceived. Uuups!
However, is this odd story possible at all?
It is, even though there are only a handful of documented cases of bipaternal twins in the world. The rare phenomenon is known as heteropaternal superfecundation (published for the first time in 1994 in the Journal of Forensic Sciences by a Chinese(!) group).
The biological mechanism is simple: a woman can release more than one egg during ovulation and if she has sexual intercourse with more than one partner at that time, sperm from different partners can fertilize different eggs.
While there are only a few cases known, studies published by the NIH and other sources suggest that approximately 2 to 8 percent of fraternal twin sets are bi-paternal.
Look out for the unexpected, if you are thinking about a paternity test!
Lousy DNA analysis fools German police
The mysterious phantom killer the German police was searching after for years has finally been identified: it is a cotton swab. The photo below shows the wrongdoer after its arrest by a police investigator.
The search was extensive and sometimes extremely dangerous as you can see on this top secret snapshot taken by accident in 2004 (showing two brave cops hunting the dangerous phantom, doing their very best). Unfortunately, they grabbed the wrong person at that time.
Now, however, after DNA traces of the phantom (pointing at an unknown, criminal woman) have been found at 40 crime scenes, the police was successful. After spending millions of Euros and spinning the wheels of a 100-person investigation unit searching for “The Woman Without a Face” - who had been linked to six murders as well as to summerhouse burglaries - the German police revealed that they have been chasing after the DNA of a factory worker who handled the cotton swabs used by police lab workers.
In other words: the mystical person, often described as “the country’s most dangerous woman”, doesn’t exist a bit (or, more precisely, is a contamination on cotton swabs).
Ouch!!
The investigators suspect that certain batches of cotton swabs were contaminated before delivery. Although cotton swabs are sterilised before being used in investigations, they are often contaminated by human DNA from skin or sweat. Every forensic scientist who is in his right mind knows that and uses DNA-free swabs (to get more information on contamination problems, read, for example, this review from 2005: “Identifying and Preventing DNA Contamination in a DNA-Typing Laboratory”).
To quote this review: “[…] It is often easier, less time-consuming and more reassuring to simply discard all solutions that have come into contact with samples that demonstrate contamination.” and “For equipment that cannot be treated with bleach, exposure to ultraviolet light can eliminate DNA contaminants.”
The German police’s experts didn’t heed these advices. They rather put a €300,000 reward on their phantom and continued fishing in murky waters.
Now, many forensic scientists wonder about the simple-mindedness of their police colleagues at the German LKAs (the State Offices of Criminal Investigation where DNA traces from crime scenes are analysed). Are such lousy DNA analyses more exception than rule there, or vice versa?
Brenner’s kidding
South African biologist Sydney Brenner is a scientific icon of the “Golden Age” of molecular biology. The 2002 Nobel prize laureate was one of the first people to see the Watson-Crick model of the structure of DNA in 1953 (he was working at the nearby Oxford University’s Chemistry Department at that time). In the course of time, Brenner became one of the greatest biologists of the 20th century.
The man with the impressive eyebrows has made several epoch-making contributions to the emerging molecular biology in the 1960s (including the identification of mRNA, helping to elucidate the triplet nature of the genetic code regarding protein translation and frame shift mutations and establishing the soil roundworm Caenorhabditis elegans as a model organism for the investigation of animal development).
However, he is not only a leading researcher. Brenner is a humorous person, too (some even say he is a hopeless joker).
From January 1994 to December 2000 Brenner wrote a column for Current Biology, initially called Loose Ends
(renamed False Starts in 1998, when the column was moved from the back of the journal to the front). The entire set of Brenner’s pieces is available free via http://www.cell.com/current-biology/Brenner.
If you prefer the “living” Brenner, watch this interview from 23rd August 2007 with a good-humoured Brenner talking about why he had only dreamt of food for two years after he had come to the UK, how Watson & Crick killed all his joy and how science works like a medieval guild with journeyman and apprentices.
And if you are a synthetic biology aficionado, you should indulge in the following YouTube video, recorded in Oct 2008 at the Synthetic Biology 4.0 Conference at Hong Kong University (arranged by the BioBricks Foundation). It lasts 36 minutes but it’s worth it. Brenner is perpetually kidding the listening synthetic biology community (while philosophising on the reproduction of centaurs, on dragons and cookies, on the ‘Biofool’ industry, on human biofuel walking around on two legs etc.). - Enjoy!
Cool youtube movies #1
Tired of everyday’s boring lab routine? Let’s change the channel and take a look at YouTube where really cool stuff can be found, such as …
… the Large Hadron Rap (referring to CERN’s Large Hadron Collider) whose backup-dancers, ha-ha, prefer anonymity, according to the credits (and I know why they prefer it!).
A more comical clip is the Creation Science 101 song by Californian satirical singer-songwriter and guitarist Roy Zimmerman. Enjoy!
Also screamingly funny are these Ali G classics on science (“…would it be possible to multiply nine-nine-nine-nine-nine-nine-nine-nine-nine…”) and medical ethics (“…you are a homophobic doctor!?” – “No, no, I’m a homeopathic doctor!”).
More serious stuff desired? Well, just watch computer-game-hero Will Wright talking about The Science behind Spore – even though seriousness doesn’t seem to be Wright’s middle name (just pay attention to the label “Composed of matter, anti-matter AND it doesn’t matter” behind him…!!).
Here are two legerdemains for your next party…
- the nail trick (how to balance ten nails on the head of one),
- the water and pepper trick (nice visualisation of surface tension),
… the ultimate YouTube short film, however, is the cool real-life μ-Tetris under a microscope (by optically trapping 42 glass microspheres with 1 μm diameter, weighting 1 picogram each of them, in a 25 μm x 20 μm sized area under a microscope).
Wow!!!
The most useful genome for committing a crime
What is the optimal qualification to get out of a tight spot after you have committed a crime? Coolness? Unscrupulousness? Brutality? Exceptional intelligence? Or stupid constables (LOL)?
The unexpected answer is that the optimal qualification for a thug to get away without punishment is to have the adequate, well, genome. No, dude, I am not speaking of a cryptic “crime gene” or something like that.
You need a… well, it’s a really bizarre story.
Did you notice the jewellery robbery in Berlin in January? It was a spectacular coup, just as in the 1964 heist film Topkapi – three people had abseiled through a skylight into the German shopping mall KaDeWe with a rope-ladder and had stolen jewels amounting to €5 million (the masked men were filmed by a security camera). Two of the Berlin bandits were caught by the police soon after the theft while the third one still is on the run.
There is a startling detail around this robbery: while forensic scientists have found (and successfully analysed) the burglars’ DNA, they cannot use this DNA as evidence anyway.
Yes, you can believe me! It’s impossible to convict the two burglars that are arrested on remand by genetic fingerprinting (at least for the German justice). Why?
Quite simply, the suspects are monozygotic twins. They have identical DNA, so it is not possible to distinguish one from another (at least for the German authorities who are only allowed to analyse eight VNTR loci in criminal cases).
Before the court “twin A” would lay the blame on “twin B” and “twin B” would lay the blame on “twin A”. Hence the judge would be unable to convict any of them.
Are the German police a dead duck in this special case? It seems so.
However, if the police were allowed to check and compare the twins’ V(D)J regions (in B cells), the situation would change dramatically. These V(D)J regions contain genes that play important roles in the immune system. They are different, even in monozygotic twins.
The web’s most popular genes
Recently, your Mr. Gene was crouching in front of his good old computer when, all of a sudden, it crossed his mind to google the word, well, “gene”.
Having performed this, Mr. Gene proudly presents the ultimate Gene Ranking, powered by Google:
1) Placed 1st is Gene, Elsevier’s International Journal of Functional and Evolutionary Genomics. If you wish to chat with Gene’s Editor-in-Chief, Dr Batzer, please address to the Department of Biological Sciences at Louisiana State University, Baton Rouge, Louisiana. And if you wish to publish your next paper in Gene you should have top-quality results. Gene has an impact factor of 2.871.
2) On the 2nd position the Wikipedia headword “gene” is ranked (how on earth did Elsevier’s Gene manage to be ranked higher than Wikipedia’s???). – Anyway, the Wikipedia “gene” entry contains plethora of genetic material – more than 6,000 words on history, structure and concept of, well, genes (the equivalent of nearly 20 book pages!)
3) The genetic bronze medal goes to the US National Center for Biotechnology Information (NCBI), the well-known resource for molecular biology information established in 1988. Is anybody unaware of this exhaustible gateway to literature and molecular databases as well as tools and useful software? I don’t think so.
However, there are many more interesting or even bizarre “gene” websites at Google’s first 20 positionings, such as…
… the Movie Maze entry for actor Gene Hackman (rank 6!!!),
… the shareware genealogy database “Gene 4.3.4” for Macintosh computers (rank 9),
… and, surprisingly far from the podium, Genentech’s famous www.gene.com domain (rank 10).
Wondering where your Mr. Gene finishes?
Mr. Gene ranks 40th, that is not half bad considering the fact that the HUGO Gene Nomenclature Committee is ranked 56th; Encyclopaedia Britannica’s “gene” entry finishes as 70th – and Gene Kelly’s 4:36 minute YouTube appearance with I’m singing in the rain places at a poor 135th rank.
The oldest DNA ever found?
Genes ordered at your friendly Mr Gene’s store are as fresh as can be (a point of honour, of course!). That freshness, however, isn’t really the case with the “dirt DNA” that has been digged up by Danish biologist Eske Willerslev.
Willerslev, the head of the “Ancient DNA and Evolution” lab, is a professor at the University of Copenhagen. He likes to hang around in really barren landscapes. 1991, for example, he enjoyed collecting megafauna fossils in North Eastern Siberia, while later, he lived as a trapper among the local Yukagihr people for six-months. Since then, Willerslev again was on the roam in nice spots such as Western Greenland and Northern Canada, collecting ancient coprolites and sediment samples for DNA analyses.
Collecting coprolites and sediments at minus degrees – really nice activities, aren’t they? And, what for the world, did this professor believe to discover inside frozen faeces?
Well, the answer is quite simply ancient DNA. VERY ancient DNA. Inside Siberian permafrost the 36-year-old adventurer from Copenhagen discovered 300,000- to 400,000-year-old DNA of mammoths, bison and mosses.
In short: he discovered the most ancient DNA ever found on Earth by more than 200,000 years.
In 2007, a readable feature on Willerslev was published in Science.
Long ago, Willerslev had pioneered the “dirt DNA” field meaning “the extraction and cloning of plant and animal DNA from just a few grams of soil and ice” (read an interesting Science feature from 2003 on Willerslev’s startling discovery Ancient DNA Pulled From Soil and Willerslev’s original Science paper on the same topic).
Recently, Willerslev broke his own record for the oldest DNA ever recovered finding DNA traces that are possibly 800,000 years old (Ancient Biomolecules from Deep Ice Cores …, DOI: 10.1126/science.1141758).
Btw, scientists always assumed DNA older than 100,000 years being analysable as science fiction (remember the scornful laughter on Jurassic Park!).
Willerslev doesn’t give a damn about such doom-mongering. He is already eyeing Antarctica where ice temperatures going down to -50°C may have kept DNA preserved longer than at any other place.
Order non optimized
This tutorial shows how to order genes without optimizationPlease note: 
Adobe Flash player needed!
How to order
After you have uploaded your sequence you can order or create a quote document.
Please note: Adobe Flash player needed!
Let me know which steps you think should be made more convenient?
How to optimize
This tutorial shows how to optimize genes using mrgene.com
Please note: Adobe Flash player needed!
Feel free to post comments on how to improve the usability!
