Genetics & Molecular Biology

Scientists have developed the first cell controlled by a synthetic genome which may allow them to probe the basic machinery of life and engineer bacteria specially designed to solve environmental or energy problems.

The research team, led by Craig Venter, has already chemically synthesized a bacterial genome, and transplanted the genome of one bacterium to another. Now, the scientists have put both methods together, to create what they call a "synthetic cell," although only its genome is synthetic.
Researchers have programmed an autonomous molecular "robot" made out of DNA to start, move, turn, and stop while following a DNA track.

The development could ultimately lead to molecular systems that might one day be used for medical therapeutic devices and molecular-scale reconfigurable robots---robots made of many simple units that can reposition or even rebuild themselves to accomplish different tasks.

Results of the research have been published in Nature.

The traditional view of a robot is that it is "a machine that senses its environment, makes a decision, and then does something---it acts," said Erik Winfree, associate professor of computer science, computation and neural systems, and bioengineering at Caltech.

I am constantly amazed at how pathologizing variable phenomena is usually a human social agent. Consider the XY fertile Akodon females who go roaming around in South America. No other rodents seem to have told these fertile XY females that they have a  disorder of sex development (DSD). That will undoubtedly be left to some of the "powers that be" of the human species. Shall I say rats? Or shall I say of mice and men?

Scientists have identified two new genes that may be risk factors for the development of late-onset Alzheimer's disease (AD), according to a new paper in the Journal of the American Medical Association.

Using an intensive, genome-wide association analysis study (GWAS), the researchers identified two new genes at specific locations in the DNA called loci that reached the required genome-wide statistical significance threshold for the first time, thus identifying them as very likely associated with AD.
Neural stem cells have long been defined as origin of nervous system development, spontaneously giving rise to the heterogeneous multitude of cells that make up the brain. Remarkably, neural stem cells seem to have the uncanny sense to differentiate at the right time and place, and to the appropriate fate, to produce a complex network consisting of neuronal connections and supportive glial cells.
Researchers writing in Nature say they can have discovered how living cells use a limited number of genes to generate enormously complex organs such as the brain.

The team describes how a hidden code within DNA explains how a limited number of human genes can produce a vastly greater number of genetic messages. The discovery bridges a decade-old gap between our understanding of the genome and the activity of complex processes within cells, and could one day help predict or prevent diseases such as cancers and neurodegenerative disorders.

The researchers developed a new computer-assisted biological analysis method that finds 'codewords' hidden within the genome that constitute what is referred to as a 'splicing code'.
A variant of the alcohol dehydrogenase enzyme ADH1B*3 is associated with reduced rates of alcohol dependence (AD), according to a study in Alcoholism: Clinical&Experimental Research.

The enzyme variant appears to cause sedation and reduce the amount alcohol a person will drink.  ADH1B*3 is found almost exclusively in populations with African ancestry, the study's authors say.
Using ancient DNA preserved in bones from Siberian mammoths 25,000 to 43,000 years old, scientists have brought the primary component of the specimens' blood "back to life."

The seven-year research effort, detailed this week in Nature Genetics, reveals special evolutionary adaptations that allowed the mammoth to cool its extremities down in harsh Arctic conditions to minimize heat loss.

The findings will also help scientists study the DNA of other extinct species, such as Australian marsupials.

If you ever looked at the inside of a computer, you would find intricate wirings and connections. But the computer is essentially useless until you’ve downloaded all the necessary software and applications. In a way, this analogy could be applied to the workings of the brain. The brain is essentially a circuitry consisting of billions of neuronal connections (or synapses) that is infinitely more complex than the typical computer hardware.
Molecules called microRNA can silence genes that protect the genome from cancer-causing mutations, say Ohio State researchers writing in PNAS. Their study shows that microRNA-155 (miR-155) can inhibit the activity of genes that normally correct the damage when the wrong bases are paired in DNA.

The loss or silencing of these genes, which are called mismatch repair genes, causes inherited cancer-susceptibility syndromes and contributes to the progression of colorectal, uterine, ovarian and other cancers.

"Our findings suggest that miR-155 expression might be an important stratification factor in the prognosis and treatment of cancer patients," says Dr. Carlo M. Croce, from Ohio State's Human Cancer Genetics program.