What do you get if you cross brewer’s yeast with a jellyfish and a rat?

Genetically modified organisms aren’t only crops and food but include glowing pets, spider-goats capable of producing spider silk and pigs with spinach genes but what do you get if you cross brewing yeast with a jellyfish with a rat? The answer is a cheap explosive detector and regretfully, not a new party drink that changes colour when cheese is mixed into it.

At the Temple University in Philadelphia, Pennsylvania a molecular biologist called Danny Dhanasekaran has succeeded in creating yeast, with a rat’s sense of smell that are capable of identifying the main ingredient in many explosives, trinitriluene or more commonly known as TNT. Once the yeast has detected TNT it produces a glow by employing its jellyfish abilities.

It is Dhanasekaran’s hope to invent a portable detector much cheaper then the already existing bomb detectors that employ electronic olfactory sensors. With his funding from the Defence Advanced Research Projects Agency in the Pentagon it may not be long before we see these yeast sensors in shopping centres, railway stations or built into a mobile phone sized device carried by policemen.

A rat’s olfactory senses work by allowing different odour molecules to fasten onto a specific protein which sends an electrical signal to the brain. Rats have a very accurate sense of smell as their olfactory senses contain about 500 proteins. The reason brewer’s yeast, Saccharyces cerevisiae was selected as the communications channel was because it uses the same type of protein receptors as rats, to detect pheromones for reproduction.

To alert it’s user that they are in the presence of TNT, a jellyfish gene which encodes a green fluorescent protein only visible under ultraviolet light was inserted, resulting in this jellyfish protein being activated when the specific olfactory pathway for TNT is activated.

Using this practice Dhanasekaran hopes to construct identifiers for other chemical and biological weapons. If Dhanasekaran succeeds in properly engineering the yeast, they will live up to 15 days and exist in a semi-solid film built into magazines which fit into mobile phone sized detectors.

Bibliography

Source One:
Pickrell, J 2006, ‘Instant Expert: GM Organisms’, viewed 24 March 2008, <http://www.newscientist.com/channel/life/gm-food/dn9921>

Source Two: Diesel, E, ‘Mutation Paste Gets Results!’, viewed 25 March 2008, <http://cedros.globat.com/~thebrites.org/News/MutationPasteResults.html>

Source Three:
Marks, P 2007, ‘Genetically modified yeast can sniff out explosives’, viewed 24 March 2008, <http://www.newscientist.com/channel/life/gm-food/mg19426036.000-genetically-modified-yeast--can-sniff-out-explosives.html>

Posted By: Jeffrey Hanson

Myopia and our genes

In recent years, people started to be concerned more about their health. Nearsightedness (myopia) is a disease occurres around the world; it is an essential issue because it influences quality of life significantly. According to the American Academy of Family Physicians, Myopia is the most common eye problem. It affects as much as 40 per cent of the population in the US and Europe but between 70 and 90 per cent of some Asian populations.

Myopia is the medical term for nearsightedness. People with myopia see objects more clearly when they are close to the eye, while distant objects appear blurred or fuzzy. Reading and close-up work may be clear, but distance vision is blurry.

In a long time, it is believed that myopia is caused by lifestyle. Some bad habits like reading the book too closely, reading in caliginous light, having a lot of alcoholic drink, watching screen (including TV, computer, PSP, NDSL, etc) too long... are believed to contribute to the formation of myopia.

However, according to the recent research at St. Thomas' Hospital in London, PAX6, the gene that is found on chromosome 11, is linked to myopia, and it is a fundamental gene to eye development. Since it’s such an important gene, most mutations in this gene cause major eye abnormalities. That explains why some children are born susceptible to being near-sighted; their eyes are more sensitive to the environment.

Furthermore, a variety of genetic patterns for inheriting myopia have been suggested, ranging from a recessive pattern with complete penetrance in people who are homozygotic for myopia to an autosomal dominant pattern; an autosomal recessive pattern; and various mixtures of these patterns. One explanation for this lack of agreement is that the genetic profile of high myopia (defined as a refractive error greater than -6) may differ from the low myopia. Some researchers think that high myopia may be determined by genetic factors to a greater extent than low myopia.

While the genetic factors that influence the transmission and severity of myopia may not be changed easily, some environmental factors can be modified. They include reducing close work; reading and working in good light; taking frequent breaks, maintaining good nutrition, and having more outdoor activities.

Hope you all have great eyesight.

Links:
http://www.healthypages.co.uk/newsitem.php?news=4473
http://www.annals.edu.sg/pdf_may00/saw.pdf
http://app1.chinadaily.com.cn/star/2004/0805/he19-2.html

Posted by: Wu Yuchen (41598023)

Happiness all in the genes: study

This article identifies the possibility that genes are responsible for certain personality traits. The study was carried out by researchers from the University of Edinburgh and the Queensland Institute of Medical Research. The researchers studied and rated the personalities of 973 pairs of twins. The results showed that personalities and happiness are largely hereditary and that genetically determined personality traits affect happiness. Professor Timothy Bates, one of the researchers of the study, claimed that this research is, "the beginnings of a new theory of happiness".

Actual Article:
If you think a new car or the perfect partner is going to make you happy think again, as new research says this is only possible with the help of your genes.

Researchers from the University of Edinburgh and the Queensland Institute of Medical Research in Brisbane have found personalities and happiness are largely hereditary and that genetically-determined personality traits affect our happiness.

The research, published in the latest issue of the journal Psychological Science, rated the personalities of 973 pairs of twins.

The twins were rated using the Five Factor Model of personality, which measures neuroticism, extroversion, conscientiousness, openness and agreeableness.

The study shows identical twins have a very similar personality and well-being, but fraternal twins are only around half as similar.

This suggests that genes are responsible for certain personality traits.

Those who are conscientious, extroverted and not overly neurotic are more likely to be happy and people with these personality traits tending to have a happiness "buffer" to help them through hard times.

While the researchers found happiness has its roots in our genes, half is related to our work, health or relationships.

One of the researchers, Professor Timothy Bates, says this research is the beginnings of a new theory of happiness.

"It helps us understand what was otherwise a real puzzle," he said.

"Why do people tend to show stable differences in happiness? It turns out that if we want to understand happiness, we will need to understand personality."

"An important implication is that personality traits of being outgoing, calm, and reliable provide a resource; we called it 'affective reserve' that drives future happiness."

Professor Robert Cummins, from the Australian Centre on Quality of Life at Deakin University in Melbourne, says it is in our best interests to be positive, and personality has a "set point" around which we maintain our well-being.

"The average person feels well satisfied with themselves and their life and that's the average set point ... even people with low set points feel positive," he said.

"Remaining positive in your outlook is incredibly important, it gives you a motivation for doing something when you wake up in the morning and makes you get on with life and do things."

Professor Bates says the latest research confirms most us are happy for much of the time, that we generally like who we are and we don't want to change too much.

Although he says the study could shed some light on mood disorders such as depression.

"Linking happiness to personality and a focus on the positive will help our research into therapies and ways to avoid the low end of the happiness [scale] - depression," he said.

Blog posted by: Sally Lavin.

Article by: ABC Science Online's Claudine Ryan (posted Thursday March 6, 2008).
Weblink for article: http://www.abc.net.au/news/stories/2008/03/06/2182663.htm