Genetics & Molecular Biology

The means by which proteins provide a 'border control' service, allowing cells to take up chemicals and substances from their surroundings, whilst keeping others out, is revealed in unprecedented molecular detail for the first time in Science Express.

The scientists behind the new study have visualised the structure of a protein called Microbacterium hydantoin permease, or 'Mhp1', which lives in the oily membrane that surrounds bacteria cells. It belongs to a group of proteins known as 'transporters' which help cells take up certain substances from the environment around them. This is the first time scientists have been able to show how a transporter protein opens and closes to allow molecules across the membrane and into the cell, by accurate analysis of its molecular structure in different states.

When it comes to embryo formation in the lowly fruit fly, a little molecular messiness actually leads to enhanced developmental precision, according to a study in the Oct. 14 Developmental Cell from Cincinnati Children's Hospital Medical Center.

While the fundamentals of this tiny bug's reproductive biology may seem insignificant, one day they could matter quite a bit to humans. That's because the study provides new information about how cells choose their own fates, especially in maintaining the size relationship and proportionality of body parts during embryonic development, said Jun Ma, Ph.D., a researcher in the divisions of Biomedical Informatics and Developmental Biology at Cincinnati Children's and the study's corresponding author.

Scientists at Bonn and Düsseldorf Universities investigated over 500,000 positions in the human genome and found a gene variant which occurs clearly more frequently in bald men than in control persons. This means they have found a new hair loss gene, according to their study in Nature Genetics.

In 2005, these scientists had already characterized the first hair-loss gene inherited through the maternal line, which explained why hair-loss in men often reflects that of their maternal grandfathers. This newly discovered gene, on the other hand, may now account for the similarity in cranial hair growth between father and son.

To get from one cell to a complex organism, cells have to divide, travel around the body and arrange intricate shapes and specialized tissues. The best way to understand these dynamic processes is to look at what happens in the first few hours of life in every part of an embryo. While this is possible with invertebrates with a few hundred cells, like worms, it was previously impossible to achieve for vertebrates.

“Imagine following all inhabitants of a town over the course of one day using a telescope in space. This comes close to tracking the 10 thousands of cells that make up a vertebrate embryo – only that the cells move in three dimensions,” says Philipp Keller. Together with Annette Schmidt he carried out the research in the labs of Jochen Wittbrodt and Ernst Stelzer at the European Molecular Biology Laboratory (EMBL).


In the beginning...


Osamu Shimomura of Marine Biological Laboratory (MBL), Woods Hole, MA, USA; Martin Chalfie of Columbia University, New York, NY, USA, and Roger Y. Tsien of the University of California, San Diego, CA, USA were awarded the Nobel Prize in Chemistry for the discovery and development of Green Florescent Protein from jellyfish, GFP.


Let there be light

Osamu Shimomura isolated GFP from the jellyfish Aequorea victoria, which lives off the west coast of North America. GFP glows bright green under ultraviolet light.

Divided the light from the darkness
This year's Nobel Prize in Chemistry goes to three scientists responsible for transforming a green-glowing jellyfish protein into a ubiquitous tool in molecular biology. Green fluorescent protein (or GFP in lab jargon) and its various colored relatives have made many previously impossible experiments cheap and easy, and you would be hard-pressed to find any molecular or cell biologists who have never used some variant of GFP. There is no denying the influence of GFP, but was its discovery Nobel-caliber?


San Diego Beach Scene, Fluorescent E. coli on agar, Nathan Shaner, photography by Paul Steinbach, created in the lab of Nobel Prize winner Roger Tsien, posted under the GNU Free Documentation License


There's been some comment recently about pundit John Derbyshire's belief that Obama will try to shut down biology because it has validated racism. Needless to say, Derbyshire is full of it, and he has a poor grasp of what recent genetics has actually demonstrated regarding nature, nurture, and race.
Scientists at the University of Leicester, where genetic 'fingerprinting' was invented by Professor Sir Alec Jeffreys, say they are developing techniques which may one day allow police to work out someone’s surname from DNA alone.

Research by Turi King has shown that, unsurprisingly, men with the same British surname are highly likely to be genetically linked even in today's multicultural world. The results of her research have implications in the fields of forensics, genealogy, epidemiology and the history of surnames.

On Wednesday 8th October Dr King will present the key findings of her Ph.D. research in which she recruited over two and a half thousand men bearing over 500 different surnames to take part in the study. Carried out in Professor Mark Jobling’s lab, Dr Turi King’s research involved exploring this potential link between surname and Y chromosome type.

Howard Berg is a physicist turned systems biologist, and he's been a systems biologist long before it was trendy to be one. He's one of the smartest systems biologists around, and a nice guy too (one who was nice enough to sit down for lunch next to an alone, confused, awkward grad student who I'm sure came off as a tremendously boring person...) Berg has devoted his career to understanding information processing in E. coli, and this week in PNAS he describes a physical model of how E. coli senses food in its environment.

I am obsessed with CSI (excluding CSI Miami, David Caruso is just too smarmy). I simply can’t help it. I will watch an episode of CSI that I have already seen twice, just for the thrill of seeing the cases unfold. I even downloaded the entire first season of CSI and watched every single episode, back to back, without sleeping. I know that I am not alone. Shows like CSI have swept the nation due partly to its drama, but also to its science. The fact that a single hair, nail or swath of skin could yield a lead on a case is captivating. It is also true.

Granted shows like CSI sensationalize the lab work and results yielded by forensic science, but its basis is accurate. DNA profiling is one of the most valuable tools used by law enforcement and in fact does help to solve cases.