2007 May

A Child’s Understanding of Reproduction and Sex Chromosomes

by Dr. Hsien-Hsien Lei
Posted May 31, 2007 in DNA in General

Janet at Adventures in Ethics and Science often features her children’s (sprogs’) drawings of nature and science. Today, she asked:

What do you find most challenging or scary about talking about science with kids?

For me, I find it most difficult to explain things at the appropriate level for a four-year-old. It’s hard to figure out what exactly my son understands and needs to know.

For example, he has a number of human body books, some with more details than others. After going through the Robert Winston Body book, he drew the following picture today that included a sperm and egg each labeled with the letter X (upper left quadrant of the circle below). I’ll do the proud parent stretch and assume those are X chromosomes.

sperm and egg

Yesterday, he drew a similar picture that included a depiction of the uterus and ovaries. Thankfully, he hasn’t asked any more questions like how the sperm and the egg meet and I’m not sure how I’ll explain it! I might just refer to the books and say that if it isn’t in there, we’ll talk about it another time. Some parents, though, literally tear these types of pages out of their children’s books. To me, that’s scarier than trying to explain it to them.

Are there any science topics you avoid discussing with your children?

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London Bus Drivers Get DNA Spit Kits

by Dr. Hsien-Hsien Lei
Posted May 31, 2007 in DNA and the Law

Last month, Scottish firefighters were issued DNA collection kits to catch miscreants who spit on them. Saliva samples are sent to the police for processing and matched against the national DNA database. Even if there is no match, the DNA will still be stored in case the spitter strikes again.

london busNow London bus drivers will also be carrying DNA spit kits. Subway stations (aka the London Underground and the Tube) already have them and Transport for London claims that 7 out of 10 samples submitted match a DNA profile in the national database. It’s part of a plan to curb “anti-social behaviour” although I’m not sure if an offender could be caught after the fact since I’m assuming spitting is usually a hit-and-run incident.

Just on my ride home this afternoon, I witnessed a couple of belligerent passengers. If they had spit, I would have loved to see the bus driver whip out a DNA collection kit and put the fear of genetics into them.

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DNA In Your Food

by Dr. Hsien-Hsien Lei
Posted May 31, 2007 in DNA Testing, DNA in General, Genetically Modified Foods and Organisms

Is DNA safe to eat? You may not have thought about it before, but you actually eat plant and animal DNA every day (assuming you’re not vegetarian, of course). In fact, there’s a whole industry set-up around testing the DNA of our food source.

Earlier this month, Therion International helped identify fake red snapper being served at sushi restaurants in Chicago. DNA tests showed they were actually selling tilapia and red sea bream instead. Another such company, IdentiGEN, has developed DNA TraceBack – a technique which checks on the path a piece of meat has taken from the ranch to your mouth. IdentiGEN calls DNA “nature’s bar code.” DNA tests are also performed on food to make sure that it is not genetically modified.

Other foods that have been verified using DNA tests:

  • basmati riceRice – basmati or other
  • Vareties of potato
  • Durum wheat for pasta
  • Composition of fruit pastes and pulps
  • Purity of olive oil
  • Varieties of tea and coffee

And here’s a myth about genes and food addressed by Biotechnology Australia:

Myth: GM food means that we’d be eating genes and it’s not natural to eat another organism’s genes.

Fact:

It’s impossible to eat without eating genes.

Every organism contains genes. When we eat an apple, we eat the genes in the DNA contained within its cells. These genes in the apple are ‘foreign’ genes, but they don’t have any effect on us because they are digested. The same goes for eating meat.

For more on the DNA testing of food, see this Food Manufacture article: The gene is out of the bottle.

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DNA Blogging at IBM’s HealthNex

by Dr. Hsien-Hsien Lei
Posted May 30, 2007 in DNA in General

healthcareDid you know IBM is involved in healthcare? Not only is their technology used on a daily basis to organize health-related information, electronic health records, biobanking, etc., they’re also interested in developing healthcare that is “networked and patient-centric.” Today, I am guest blogging at IBM’s HealthNex on the top 10 ways DNA technology will change your life. Here’s the bare bones list, please visit HealthNex to learn more!

10. DNA makes you hip.
9. DNA is an artistic influence.
8. DNA brings you closer to your family.
7. DNA is a lucrative career choice.
6. DNA technology inspires other forms of useful tech.
5. Your DNA may soon be collected for government databases.
4. DNA may determine your eligibility for a job or insurance coverage.
3. You can put your DNA to work in the privacy of your own home.
2. Because parents can preselect certain traits in their children using preimplanation genetic diagnosis and other DNA technology, our population demographics will also be changing.
1. DNA technology will make it possible for us to receive personalized medical care that’s tailored for us.

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Genes for Learning Languages

by Dr. Hsien-Hsien Lei
Posted May 30, 2007 in DNA in General

I couldn’t do my Chinese homework because I lack the genes for tonal language.

~Imaginary Student’s Excuse

Creative, but no go. A recent study has found that two genes, ASPM and Microcephalin, may determine a person’s propensity for speaking tonal languages, like Chinese, back when languages were still evolving. These genes involved in brain development may have tipped some people to speak nontonal languages, like English, and probably evolved around 5,800 years ago. For more information, the authors have a layman’s description of their study online.

eating chinese food 1The most important takeaway message is that these kinds of data should not keep anyone from learning a new language. As with most behaviors, just because it might be easier for us to do one thing doesn’t mean that’s the only thing we should do. It strikes at the heart of genetic determinism. Do our genes determine what we do or do we? I believe in the latter. Challenges, genetic or otherwise, can be overcome with hard work.* Unless you’re this man in the cartoon who’s been gifted with a new brain.

*Now, don’t argue with me over this. I know there are exceptions. But diligence goes a long way. Now get back to work!

NB: More discussion at Gene Expression.

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Dr. Jim Watson’s Genome Sequenced for 2 1 Million Dollars

by Dr. Hsien-Hsien Lei
Posted May 29, 2007 in Personalities with DNA

dna dvdCongratulations to Dr. James Watson, co-discoverer of the structure of DNA, whose genome sequence will be handed to him on a DVD this week. His genome was sequenced six times over for quality control and it cost 454 Life Sciences approximately $2 $1 million dollars and a smidge less than two years compared to $4 billion dollars and 10 years for the Human Genome Project.

When “Project Jim” was announced in 2005, Dr. Watson said he didn’t not want to know what variant of the ApoE gene he had. Another leader in the intial sequencing of the human genome, Craig Venter, already knows that he has ApoE4, which is associated with Alzheimer’s disease.

As fascinated as I am by DNA, I don’t know if I’d ever want my entire genome sequenced. It’s not like knowing will keep me from getting hit by a bus tomorrow. ;)

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Eye on DNA Links – May 29, 2007

by Dr. Hsien-Hsien Lei
Posted May 29, 2007 in Eye on DNA Headlines

wellness

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DNA Passports for Canadians

by Dr. Hsien-Hsien Lei
Posted May 28, 2007 in DNA and the Law

canada passportJust two days ago, I thought the Russian government was crazy for issuing “genetic passports.” But as it turns out (as it often does), I’m the one who’s naive. A white paper released by the Network on North American Studies in Canada has suggested that Canadians will eventually have to incorporate DNA, biometrics, or other biological information, into passports and other travel documents when traveling to the US. The report also mentions concerns about privacy and confidentiality if such measures are taken.

In 2004, Thomas Greene wrote for The Register:

At present, it’s impossible for any bureau to know that one is who they claim to be. The only near-foolproof way to establish identity would be through universal DNA profiling at birth. After a few generations, virtually everyone could be identified with certainty, so long as DNA identification and verification is required, cradle to grave, for all transactions such as obtaining a birth, marriage, or death certificate, establishing credit, opening a bank account, buying, selling or leasing real property, registering to vote, obtaining a driver’s license or a passport, enrolling in school, registering for military service, employment, and so on. [emphasis mine]

Whatever happened to fingerprints, retinal scans, voice prints?! Sometimes it seems to me that excitement over the coolest technology blinds us to the fact that simpler, less invasive methods are still just as good.

The Star Phoenix, May 28, 2007
NB: In the caption for the Flickr photo featured above, the photographer wrote, “privacy is dead.”

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Sodium Benzoate and Vitamin C in Soft Drinks Damage Mitochondrial DNA

by Dr. Hsien-Hsien Lei
Posted May 28, 2007 in DNA and Disease, DNA in General

coke bookCoke is my favorite remedy for a lousy day. It’s also my favorite reward post-vacuuming. (Don’t scoff. I live in a four-level house with three staircases.) But if I know what’s good for my DNA, I may need to break my Coke habit.

Sodium benzoate aka E211, a preservative used in carbonated drinks, can form carcinogen benzene when mixed with vitamin C (ascorbic acid). Four brands have already been removed from the market in 2006. Professor Peter Piper has found that sodium benzoate can damage mitochondrial DNA.

The mitochondria consumes the oxygen to give you energy and if you damage it – as happens in a number if diseased states – then the cell starts to malfunction very seriously. And there is a whole array of diseases that are now being tied to damage to this DNA – Parkinson’s and quite a lot of neuro-degenerative diseases, but above all the whole process of ageing.

Two of the drinks that were pulled last year were Fanta Pineapple and Vault Zero. Coca-Cola voluntarily reformulated the products and agreed to settle with four plaintiffs who claimed that the two drinks were a breach of warranty and represented unfair and deceptive trade practices.

For some reason, I thought an urban legend about Coke and cancer had circulated some time before but there’s no listing at Snopes.com. It’s certainly one of those stories that surfaces again and again. In 2006, the BBC reported on benzene in British soft drinks at eight times the level permitted in drinking water. My own consumption of soft drinks is at around one bottle a week so I’m not too concerned. I hope nobody’s drinking more soft drinks than water although I’m sure plenty do.

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DNA in ASCII

by Dr. Hsien-Hsien Lei
Posted May 27, 2007 in DNA Fun

DNA rendered in ASCII text “DNA” using Google Image Search and Toogle.

DNA in ascii

via Neatorama

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(3 comments)


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